"... but it’s not incumbent on any platform to provide the megaphone for lunatic fringe conspiracy theories grounded in fantasyland."

Here's the thing. I understand why that's a common position, but I still disagree with it. When any entity is SO MUCH a part of public discourse that politicians using it can't legally block anyone, that's a part of the public square. And part of being the public square means allowing crazy people to use it sometimes. That's just the cost of doing business. We may not like it that Facebook or Twitter have become a significant political platforms. I don't. I hardly ever use either, especially for anything related to politics. But a huge number of people do. That's where we are, and we're going to have to figure out how to deal with it.

As far as China, I plead ignorance. I have a decent handle on the technical aspects of Chinese censorship, but the social and legal ones, not so much. I wouldn't know where to begin making a comparison.