On the other hand, others see this power and want to use it. Thus recently we see a lot of "they are a private company, they can do whatever they want" when somebody likes how they handle some situation and "they have become too powerful, they need to be regulated" when somebody doesn't like that. This is a kind of a game where whoever makes facebook do their bidding wins, and facebook itself is reduced to maneuvering between various demands and interests without much agency of their own. That's quite scary as well.
My guess is this will end up with some kind of quasi-censorship regime, "voluntarily" installed by facebook (because, you know, first amendment), so that they can continue to collect their ad dollars unmolested. The beginnings are already there - various fact-checkers etc.