> far less moderation and tone policing

This feels like maybe even the majority of the problem.

In general corporate social media favors memetic content and disfavors "inconvenient" content. Inconvenient meaning things that cause non-trivial numbers of users to mash the thumbs down or "report content" button. The premise of that is supposed to be that people are reporting spam and trolling etc.

The problem naturally being that people will also use the platform's "make it go away" mechanism to penalize anyone who tells them things they don't want to hear. And then the sort of people who insist on telling the technical truth even when it's inconsistent with the political lie tend to get shadow banned into irrelevance, which leaves what in everyone's feed instead?

That’s a ZIRP problem. You didn’t have massive sprawl communities until the investment was there to build systems to keep Nazis and trolls away.

Slashdot really highlighted this for me - if you followed the site and the core forum of founders, dealing with moderation was horrible. The writing of CmdrTaco over the years really made it sound like it just made him miserable.