I do worry about the consequences of Twitter, Reddit, et al banning the more marginal content, though.

When The_Donald was on reddit, it was more easily monitored in one place. People who used it at least were forced to confront evidence daily that they weren't holding the majority opinion. And grownups from the platform could remove (and report to LE) the worst stuff.

When you ban those people from mainstream platforms, you do deny them some of an audience. But you also encourage them to make their own echo chambers and congregate elsewhere, which may be on the balance worse.

Now we see the same things happening with Twitter / Parler and Gab.

It's definitely hard to know where to draw the line. Karl Popper and all that.