When I was growing up in the 1980s, grey Sunday afternoons were invariably spent in front of a Carry On film, while the adults snoozed in armchairs. Despite the homophobic jibes, the fat gags and the relentless groping of female characters, the films were seen as the ultimate in family entertainment. They didn’t seem so bad at the time. At the very least, we can credit Carry On Cleo, which starred Kenneth Williams as a neurotic Caesar, with giving us one of the great comic lines: “Infamy, infamy, they’ve all got it in for me.”

Nowadays we might reasonably look upon the worst of the Carry On franchise as we do an elderly relative whose generous distribution of Werther’s Originals is accompanied by a stream of low-level bigotry. Certainly, primitive sight gags around bursting cleavages, and scripts that did somersaults in order to get Williams to utter the word “queer”, are more likely to make us cringe than cackle. As for the “browning up” of Bernard Bresslaw in Carry On Up the Khyber, let’s not even go there. And yet, Carry On nostalgia endures both in the national consciousness and in the intermittent efforts of film producers to reanimate the brand.

This week has brought news that a comeback is on the horizon courtesy of the producer Brian Baker, who has been engaged in a lengthy legal battle with ITV, which owns the franchise, and who has finally been granted permission to fund a new movie. It’s by no means the first time a reboot has been proposed.

In the early 1980s there was talk of Carry On Dallas, inspired by the American soap, a project that seemed surplus to requirements given the original’s capacity for self-parody. Happily, it never got off the ground. In 1992 the threat of a revival was carried through in the execrable Carry On Columbus. Not for nothing was it later designated the worst British film ever made, thus sealing the franchise’s latter-day reputation as a peddler of smirking, lowest-common-denominator tat.

Why, then, do we persist in celebrating it? Would it be better simply to draw a veil over this apparently unedifying chapter in our cultural history? Viewed from a distance, the prejudice on display certainly isn’t pretty. Study the films more closely, however, and they also highlight much of what we have lost.

When the first film, Carry On Sergeant, hit cinemas in 1958, expectations weren’t high. An attempt to cash in on the popularity of The Army Game, a Granada sitcom about postwar army life, it saw a soon-to-be-retired sergeant trying to turn a hopeless bunch of recruits into functioning soldiers. Shot in just a few weeks on a microscopic budget, it was nonetheless a hit, and a British institution was born. The series peaked commercially in the 1960s with Carry On Cleo, Carry On Doctor and Carry On Up the Khyber. It’s no coincidence that these titles arrived at a time of low unemployment and improved living standards, and when Harold Wilson, a former grammar school boy from Yorkshire, was prime minister. Carry On films were by no means radical social documents, but they nonetheless reflected the collapse of the age of deference and the strides made towards social equality. Compare that to where we are now, marooned in an era of stagnating wages, rising homelessness and record food-bank usage, with a bunch of public schoolboys gambling with Britain’s political future.

These shallow, knockabout comedies had at their heart a distrust of authority, and never missed an opportunity to skewer the pomposity of supposed superiors. In the first film, it’s army sergeants that are deemed ripe for ribbing; later it’s teachers, doctors, police constables and the grand poobahs of the British Raj. Putting aside the grim racist tropes in Carry On Up the Khyber, we see a film at once nostalgic for the empire while lampooning the vulgarity and arrogance of the British upper classes and their fabled stiff upper lip. Meanwhile, Carry On Nurse, the highest-grossing film of 1959, cast an unlikely spotlight on Britain’s new National Health Service.

More broadly, in catering to a working-class audience, the Carry On films offered cinemagoers a chance to see versions of themselves on screen – a novelty however much they were caricatured. Look at the casting, too, and you see a film industry opening its doors to those who might previously have been consigned to below-stairs roles, or overlooked entirely. The franchise made stars of Kenneth Williams (son of a barber), Barbara Windsor (daughter of a fruit and veg seller), Sid James (a Jewish hairdresser) and Joan Sims (daughter of an Essex stationmaster). It’s hard not to compare this to today’s actors, increasingly the product of expensive educations and cushioned by family money. In a recent interview, the actor Vicky McClure spoke furiously of the advantages enjoyed by actors who have never encountered financial hardship – “if you haven’t got the funds, you haven’t got the same opportunities”.

The Carry On films undoubtedly outstayed their welcome. With each striving to be bawdier and more outrageous than the last, they lost the daft humour that flourished in the era of censorship and struggled to find an identity in an increasingly permissive society. The final two pictures before the 1992 comeback – Carry On England (1976) and the odious Carry On Emmanuelle (1978) – bombed. Do we need a reboot? Of course not. The films were the product of a time and place and any efforts to make them palatable for today’s audiences will surely end in disaster. But to write them off entirely on account of their flaws would seem similarly ill-judged. Such hoary old relics are worthy of our reflection, showing us how far we have come, while reminding us what is yet to be done.

• Fiona Sturges is an arts writer specialising in books, music, podcasting and TV

• This article was amended on 4 July 2019. An editing error led to it saying that Sid James’s father was a hairdresser, whereas in fact it was Sid James himself