The revelations from the twitter files show that this is true. Social media works in tandem with US Federal Agencies to review what people see or don't.

and checks and balances allowed it to eventually come out, even though i think facebook knew they could fight it in court. In China that is not an option, Xi and his circle say is what happens with no recourse other than a straight up rebellion by the people of China.

Via various incentives and regulation, they kind of can

Which can be openly discussed, critiqued, etc. Or in the case of X, bought up by a private citizen and turned into a completely different animal. There's important and significant similarities, but they are worlds apart.

You'd be surprised on how much government has their hands in US big tech companies.