I don't think that's necessarily true - maybe it depends on (a) the owners of the platform and/or (b) whether there are sources of funding besides advertising
E.g. here in the UK, the BBC and Channel 4 are both broadcasters owned by the government, and both are funded at least in part by adverts. But I think both of them are relatively healthy and aren't on the brink of destroying themselves.
I think most of the BBC's funding comes from the licence fee (British people pay for a TV licence) but they make some money from ads shown to international audiences. Channel 4 is solely funded by adverts I think, but it's owned by the government and I think they have to abide by certain rules and targets.
In the UK the BBC only has advertisements for its own content, nothing else. As bad as its got since Tony Blair and David Cameron both undermined its independence and quality, at least there are no ad breaks in its shows.
True, they don't show commercial adverts in the UK, but they do to other countries. People outside the UK can access the BBC website but they'll see adverts on there, and apparently BBC America (shown in the US) has commercial adverts
And Channel 4 of course does show commercial adverts in the UK, but I think they still make some decent content, and I don't think they're on the verge of self-destruction
Maybe the real problem is when an entity is chasing profits, because Channel 4 isn't a normal for-profit business, since they're owned by the government, and I think they have to abide by some rules
But then you could look at Channel 4, which does show ads to UK people, but I think Channel 4 is still okay and I don't think it has been ruined by ads. So maybe a profit motive is what causes enshittification, rather than just ads. I definitely hate ads but maybe ads alone don't destroy platforms.
You won't get any disagreement from me on the corrosive effects of advertising.
I do think that Channel 4 used to regularly produce greater content than it can now. But that probably is more to do with advertising revenue being leeched away to online platforms and the growth of its direct competitors.
Interesting, maybe the content has changed, I probably don't watch enough TV to have noticed. But I think Channel 4 news is pretty good, and I liked their Paralympics coverage.
They've still got a good reputation for news. So good that after a few combative interviews with Tory MPs (back when they were in power a few years ago) the Culture Secretary wanted to sell the channel off.
Don't get me wrong they can still produce the occasional good comedy or documentary but they used to do so consistently.
True, I remember the government trying to sell off Channel 4. Anyway I guess my point was that ads don't necessarily ruin a platform if the platform has a decent purpose other than just profit... although I definitely do hate seeing any ads, even on Channel 4 or anything else.