Alex Ferguson is gone and his golden era has been replaced by defeat and a mounting sense of crisis. Many blame David Moyes, others the club's billionaire owners. But is the root of the malaise deeper still?

When it comes to football and talk of crisis, it is always best to take the long view. This is, after all, an industry that is pretty much always in crisis, sirens howling, warning lights on, seawater lapping around your ankles, where the band just carries on tinkling away and people keep turning up on deck asking where the party is. On Wednesday night, Manchester United will play Bayern Munich in the quarter finals of the Champions League at the illuminated sunken space-doughnut that is the Allianz Arena, a fixture of such glamour it is almost tempting to forget that United are, by all reports, a club in crisis.

Indeed, over the last few months the ongoing crisis of Manchester United has been discussed so widely it has become an object of daily fascination, like the weather forecast, or the collapse of Ukraine. This is the way of these things now. Consumed by rolling news and social media, English football finds itself in the grip of an unceasing background din. It is a place where enraged public opinion has become an event in itself, and where everybody on every side of the argument is simultaneously distraught and consumed with gurgling triumphalism pretty much all the time.

And yet, for all the talk, there are plenty of questions to be answered as Britain's most celebrated football club of the last 20 years embarks on its date among the Euro-giants. Are United really in crisis? If so, is this the kind of crisis most people seem to imagine – a business of botched succession and managed corporate shrinkage – or another, more insidious, kind of crisis altogether? All that is certain right now is that it seems to matter, on some level, to a great many people.

In outline the facts of United's case are fairly plain. The team has struggled on the pitch and in the transfer window from the moment last July when David Moyes was first unveiled as Alex Ferguson's replacement, posing for the cameras by the home dugout with a pallid grimace of a smile, like some incredulous new father about to wander out of the maternity unit for the first time with his papoose on upside down.

United have lost 10 times in the Premier League this season and will fail to finish in the top four for the first time in 23 years. They have been repeatedly cuffed aside by more powerful Premier League opponents. More bafflingly, their football has been callow and cautious, lacking in a familiar sense of United-tinged dash. And tellingly it is this change of tone that appears to have been most disorientating. Football teams will lose, empires will crumble, but there is a deeper sense of status-anxiety here. Historically, United have been portrayed as a kind of footballing Camelot, its greatest teams providing an ideal of youthful attacking brio, a vehicle for a terribly seductive kind of red-shirted romance.

This is the key to the United identity, although in reality this sense of fearless attacking vim has diminished in recent years as the late stages of Alex Ferguson's time in charge coincided with some cautious, austerity-era winning football. But under Moyes, a worthy if unremarkable organiser, a curtain seems to have been swished aside, behind which this state-of-the-art United stand revealed as ... well, something that doesn't particularly look like United any more.

David Moyes: looks like a man trying to navigate the Martian criminal underworld with a boy scout compass. Photograph: John Powell/Liverpool FC via Getty Images

Some odd things have begun to happen. A fortnight ago, a group of supporters chartered a plane to fly over Old Trafford trailing the message "Wrong One – Moyes Out" and were loudly booed by most of those in the stadium, which became mini-headline news in itself. In January, a Manchester resident was recorded calling 999 and demanding to speak to Alex Ferguson after a particularly galling defeat by Sunderland. This too was widely reported. Meanwhile, at every fresh turn, the channels are jammed with grief, outrage, frantic reassurances. Why is this news? Or, more precisely, why is it such big news?

Partly, this seems to be simply a function of longevity, and perhaps even of a collective sense of ubi sunt nostalgia. Under Ferguson, United dominated the Premier League, as inaugural champions of the rebranded top tier in 1993 and its most visible presence for the next 20 years. There are currently adults alive who weren't born the last time United were anything other than an all-devouring machine fronted up by an immutable gum-chewing Scotsman.

Plus, of course, football itself changed during the years of Peak United, transformed into a relentlessly intrusive media event and generally entwining itself around everything like an aggressively territorial knotweed. Hate it, loathe it or feel utterly indifferent toward it, you can no longer simply ignore English football, to the extent that failing to be affected by United's decline, even as a vague sense of something distantly happening, of insistent concerns felt only by others, is now almost impossible.

But then United have always been an object of wider fascination, a shared sporting jewel, calling forth those familiar glimmers of English football's romantic big-city industrial past. With United, the postwar years brought the founding legend of Matt Busby's great teams of the 1950s and 60s, torn apart by the Munich plane disaster, then rebuilt with impossibly inspiring circularity to become champions of Europe.

More recently, the 90s saw the dawning of the second great age of United, spurred on by the gold-rush years of the early Premier League. Floated on the stock exchange in 1990, with a stadium in Salford that could be enlarged without planning-law restrictions, United were in the right place at exactly the right time: rich, brilliantly managed and blessed with a group of bespoke homegrown players including the dreamy talents of Paul Scholes and Ryan Giggs. David Beckham, in particular, was a gift to a Premier League hungry for heroes, a gorgeous golden dufus-child all of its own, and a poster boy for those expansionist ambitions.

And so Fergie-era United became unavoidably associated with the plastic boom times of the 90s, a decade when Tony Blair looked like an exciting young progressive prime minister in waiting and Manchester itself was recast as a modern metropolitan city, its industrial heart energetically transformed along the loft-bar-boutique model. Even now, on matchdays, Old Trafford has a rolling playlist from the baggy, fuzzy, dreamily insouciant Manchester music scene of the 90s. Bayern Munich fans have their oompah band. Barcelona have the Catalan celebration hymn. United have This is the One by the Stone Roses and I'm Free by the Soup Dragons.

It is perhaps this sense of having come to the end, not just of an era, but of that era, so closely associated with the prosperous, pre-crash teenage years of many people now in their 30s and 40s, that makes United's dip feel significant even for those who might otherwise have no wider interest. The 90s are done. The credit ran out. And now even Manchester United seem cowed, another British institution in a state of retreat.

Plus, of course, there is an element of soap opera here too, most notable in an oddly gripping parable of succession. Taking over after 27 years from arguably the most successful British manager of all time always looked like a near-impossible job. José Mourinho was the obvious choice, one of the top coaches in world football and a man who projects the kind of cartoonishly maniacal self-possession required to cast off the weight of an overbearing predecessor. On his way out at Real Madrid, Mourinho was gettable too. And yet United looked elsewhere, amid some slightly puzzling talk about Mourinho being simply not a United type, a controversialist, a trash-talker, a personage of insufficient fibre.

Alex Ferguson salutes fans after his final game in charge of United, May 2013. Photograph: Nick Potts/PA

Instead, Ferguson hand-picked his successor, plucking from the throng a well-organised, honourable man who had never managed at an elite-level club, never won a trophy, and who even now seems frazzled and jumpy just standing on the touchline at old Trafford, arms flailing, whirling around as though feeling at his back some silent, trailing spectre.

It is here that the sense of sentimental hubris around the appointment of Moyes begins to seep in. Ferguson has always drawn a certain theatrical power from his access to British football's shared managerial myth kitty, the rock'n'roll years of the formative Scottish giants Matt Busby, Bill Shankly and Jock Stein. Even in his wine-loving multimillionaire pomp, Ferguson retained a shade of this pared-back authenticity. Moyes has its imprint too. Ferguson was coached by his father, David Sr, as a boy in Drumchapel. And Moyes himself is another chiselled, stately Glasgow disciplinarian, not to mention a committed Christian who infuriated at least one teammate at Cambridge United by discussing Bible teachings in the dressing room.

This sense of retro, straight-backed decency is probably Moyes's defining quality. The idea that it makes him a like-for-like replacement for the great dictator is alarmingly off key, like a commemorative portrait of some gnarled and politicking Renaissance machiavel recreated on canvas as a milk-white model of piety. In his peak years, Ferguson was above all a pragmatist and a brilliantly effective agent of the dark arts, stretching the rules to his advantage, intimidating opponents and dominating the media. Mourinho may have provided an unflattering reflection, but he understands this world perfectly. Moyes can perhaps adapt and grow into his outsized role. But for now he still looks like a man trying to navigate the Martian criminal underworld with a boy scout compass and a map of rural Buckinghamshire. Little wonder it is all so horribly watchable.

In a sense, though, Ferguson-Moyes is no more than a sub-plot here. The fact is United have been a decelerating juggernaut for several years now, experiencing a period of declining momentum that began in earnest the moment Cristiano Ronaldo was allowed to leave the club for a world-record fee, with the money largely swallowed up by debt repayments. There is a fascinating commercial paradox to this. On the face of it, United's decade-long ownership by US retail magnates and all-round billionaire wheeler-dealers the Glazer family has been a wonderful success. The brand? Well, the brand has never been quite so energetically hammered. United currently have a staggering 35 official sponsors, including Aon, DHL, Nike, Chevrolet, Singha (official beer), Bulova (official timekeeper), Mister Potato (official savoury snack partner) and Namee (official noodles partner, Asia, Oceania and Middle East). Last year, the club announced record second-quarter revenue of £122.9m. Phew! Trebles all round!

Except, there is of course a separate game going on here. In reality, the Glazers are sweating their heavily leveraged asset as hard as they possibly can, haemorrhaging interest payments and drawing down huge cash dividends from a club bought almost entirely in loans secured against itself. It is a brilliantly worked, gravity-defying exercise in corporate plate-spinning, at the end of which we have a club still somehow staggering on down the main street of elite European football with its hands clasped to its chest, banknotes fluttering out from under its waistcoat, a piece of cloth with the word "bang!" dangling from its six-gun.

Winning streak: Paul Scholes, David Beckham, Roy Keane, Andy Cole and Ryan Giggs celebrate beating Liverpool in the fourth round of the 1999 FA Cup. Photograph: Michael Steele/Empics Sports Photo Agency

The team has naturally suffered. While other clubs spend the improbable millions of their carbon-magnate owners, at United key players have been allowed to age in situ, with spending significantly scaled back before the isolated panic buys of the past six months. For a club of stars, United lack stars. Wayne Rooney and Robin van Persie are grizzled A-listers, but Rooney has been at the club for a decade and Van Persie is 30. Even Old Trafford itself has begun to look a little jaded, its surfaces worn, facilities unrevamped since the 90s. During the home leg against Bayern Munich last week, one German photographer, crammed into the tiny snapper's hutch with a microwave pie in his hand, was asked if it was his first visit to Old Trafford. "Isn't it wonderful?" he was asked. The photographer politely kept his counsel.

The irony, of course, is that United are victims here of a situation they helped create. So broad was their profile, so thorough the Premier League's marketing triumph, that United became unavoidably attractive to the kind of people who tend to fasten on to such success stories like vampiric super-capitalist incubi. Buoyed in those early years by their own global presence, United are now being leeched by agents of precisely this system. They have simply been unlucky, attracting not the usual gallery of cash-splurging egomaniacs, but the only sensible billionaires in the business.

It is process with an endpoint too. There is a theory that the appointment of Moyes is in one sense a holding manoeuvre, a manager of limited experience inserted as a useful idiot to keep the machine rolling along with as little chafing as possible while the asset is sweated to its limits. And yet even as United are being so resourcefully milked, the brand itself will begin to wither beneath their feet. In the past, United managers who failed to win league titles – Ron Atkinson, Tommy Docherty – still looked like United managers, promoting an elegantly freewheeling brand of football, failing with grandeur, failing like United. But modern football simply doesn't allow you to play like this. It is a crowded sport, a possession game, where the team that wins is also the team that gets to play and pass and starve the opposition into invisibility.

Brands, as opposed to fanbases, are fickle things. How many Chinese teenagers, how many of United's alleged 569 million "followers" will continue to find themselves hooked on Moyes's roundheads, a team engaged at the top level in a continual rearguard against better resourced, more coherent opponents? United's hierarchy is, of course, aware of the need to compete and money has been splurged on players in the last few months. It feels like part of a keenly-managed balancing act. There is a suggestion that the Glazers may sell the club in 2017 when the current loan arrangements run out, although potential buyers will have to find at least £2bn, and will inherit a club still saddled with £500m of ownership debts. There has been talk of more direct action, of organised resistance to the progressive siphoning off of match-day income, of a cartel of well-intentioned fan-financiers making the Glazers an offer they can't refuse. Most appealing has been the suggestion of a kind of ex-player cavalry charge, with Beckham, Scholes and Gary Neville forming their own billionaire-backed group to storm the gates and take back the keep. For now, United will remain an object of precarious fascination, a great British sporting institution not so much in crisis as in the grip of a wider gravity, and hostage to a very modern kind of sporting trial.