Whether or not paywalls will prove to be the salvation of mainstream journalism is still a hotly debated topic; but there's good reason to doubt it. At both News and Fairfax, the initial figures looked promising. But steeply rising digital subscriptions soon levelled off. In the first quarter of this year, digital subscriptions to The Age and The Sydney Morning Herald actually declined, though in the second quarter they've returned to positive growth – in the Herald's case, up nearly 10 per cent year on year. Encouraging. Until, that is, you realise that print sales, from which the Herald, like most newspapers, still derives most of its advertising revenue, fell 12 per cent. Other Fairfax newspapers, The Age included, are in a similar or worse state: print sales are declining more rapidly than digital sales are increasing. As for News Corp Australia, it won't publish digital figures for most of its tabloids. The Australian's digital subscriptions show healthy growth, and its newspaper sales are declining more slowly than Fairfax's: but The Australian has hardly ever been profitable. Its ultimate fate depends, many believe, on the longevity of its founder and champion, Rupert Murdoch, far more than on its sales figures. Now both publishers are ploughing money into mobile platforms: undoubtedly, that's where demand is strongest. But if it's tough to make a buck from a newspaper website, it's harder still extracting any kind of profit from people browsing for news on their smartphones.

The challenge is to persuade those browsers to pay for a commodity – online news – that they've never paid for before. And as last week's Essential poll shows, that's hard. Nearly 70 per cent of respondents told Essential that they would "never pay for online news and information". In an article brooding about that poll, Crikey's Myriam Robin quoted Fusion Strategy's Steve Allen: "One day, [the public] will wake up and it will be a world full of inaccurate, crappy, self-serving, biased news, and they'll be going, this is all shit." All of these stories revealed abuses of the social contract that should have been prevented by state or industry regulators. Read any string of online comments about the mainstream media – including, no doubt, the comments at the end of this column – and you'll find plenty of readers who declare that the world is already full of "crappy, self-serving, biased news" that only a mug would pay for.

Well, it's a tenable argument. But the idea that we can do without the journalism that those big newsrooms generate seems to me optimistic, to say the least. Right now we have a royal commission into the institutional treatment of child abusers: that would never have come about but for the work journalists in Victoria and NSW, at News, and Fairfax, and the ABC, most notably the Newcastle Herald's Joanne McCarthy. Now, Fairfax is slashing that paper's journalistic staff more than half. We have a royal commission into trade union corruption, following up revelations in the mainstream media of egregious misuse of members' funds at the Health Services Union and elsewhere. (It's only fair to note that the blogger Peter Wicks and the small website Independent Australia were telling us for years that Kathy Jackson, far from being a heroic whistleblower, was in fact a bigger misuserof the union's funds than Craig Thomson. Not enough people, in the mainstream media, in the Gillard and Abbott governments, or the on the royal commission's staff, paid attention.)

Fairfax Media's Adele Ferguson plugged away for years to highlight the misdeeds of the Commonwealth Bank's financial planners – helped immeasurably by former planner turned whistleblower Jeff Morris. The same journalist – this time with the help of self-styled consumer advocate Michael Fraser – revealed a month ago that the 7-Eleven chain's franchisees have been underpaying their staff for years, with the knowledge and connivance of the chain's central management. Both those stories involved collaboration between Fairfax Media and the ABC's Four Corners – a collaboration that would have been unthinkable in the days of Fairfax's rivers of gold. Four Corners' own investigation earlier this year resulted in the current inquiry into the greyhound racing industry: as in its earlier expose of the mistreatment of cattle in Indonesian abattoirs, the most damning footage came from activist organisations such as Animals Australia and Animal Liberation Queensland. All of these stories revealed abuses of the social contract that should have been prevented by state or industry regulators. But ASIC, and APRA, and the Fair Work Commission, and Racing Queensland, and the Department of Agriculture, and state and federal police forces, all proved inadequate to the task – in many cases captured by the very interests they were supposed to be regulating.

The mainstream media could do, in my opinion, with tougher regulation itself; it has its share of bullies and toadies. And often, even on its best stories, a lot of the investigative grunt work is done by others – bloggers, pressure groups and whistleblowers. But without the big audiences the mainstream media command, those stories wouldn't get traction. Indeed, without its legal clout, they might not get published at all. So it still seems to me that we need a profitable mainstream media. And if we want to keep it, we need to pay for it. Jonathan Holmes is a Fairfax columnist and a former presenter of the ABC's Media Watch program.