Trump is a big baby. I deal with relatively wealthy people and I come to the conclusion that consistent complaining is how they eke out a marginal advantage that accumulates wealth over time. Sad but true.
100% agree that websites and social media platforms are private property, unless they hold a monopoly position (or move in concert). At that point, they become a utility.
I am not as worried about Facebook and Twitter, as much as the hosting services. MySpace and AOL were big social media platforms at one point, and Yahoo was king of search (and a lot of other stuff), until it wasn't. I could start a social media company tomorrow, specializing in 'Bum Pics' ?, and censor anyone who believes boobs are better!
Mmmm, wide hips... (stares off to the horizon)
Back to my point, I do imagine that it is much more difficult to build or buy the infrastructure to host said website. I don't know how many providers are out there, honestly. I know there are right-wing alternatives to FB/Twitter, but big-tech is moving to make access to their apps difficult (removing from google/apple app stores) and refusing to host their sites (Amazon).