Facebook, Twitter and YouTube are essentially monopolies in their areas of social media. The price of not being broken up as illegal monopolies should be a version of net neutrality under which they can only ban or suspend or demonetize or otherwise take action against a user for clearly illegal speech (eg cold porn, terrorism, making terroristic threats, etc).
Otherwise, they should be broken up. Their monopoly position is dangerous to freedom of speech.
I would go as far to make it so no company can own more than one kind of media.