what's more desirable: having all of the extremists congregate on one big website or shut that website down and have a diaspora of different, smaller sites that are even more extreme?
They put up fact-checks under a post sometimes, but what those fact-checks mean for the visibility of a post is left to your imagination. If a post or link is outright censored, you don't find out about it until you try to post it. As their censorship intruded even into so-called private messages on those platforms, even in a 1-to-1 conversation, sending something prohibited doesn't show any kind of "Prohibited content censored" message to the recipient (even non-spam).
They'd much rather you don't know they're censoring anything.