I guess you are not in US or UK? I agree with core utilities being publicly managed. But in UK and US the best we can hope for, for the time being, is strong and enforced regulation of those. Internet infrastructure is one thing - and ought to be publicly owned and managed. But Facebook is not internet infrastructure (however much they want to persuade some parts of the globe that it is). Those that use the internet infrastructure should be regulated, and that includes Facebook. But if you decide it should be in public ownership then where do you stop? BoingBoing?
As for those who profess that they cannot leave it, I call bullshit. I do not care what the excuse is (I’ll never be able to share with my granny, my friends in the Antarctic, my community group again, etc. If I left the other hundred people in my ‘group’ would not leave too, so I have to stay there with them) they are just not trying hard enough. Campaign among your groups, propose alternatives, and - frankly - if they wouldn’t listen I’d ask myself is this is a group I want to remain part of. Yes, that’s very ‘robust’. Yes, it allows for no subtleties. But the time has come to make Zuckerberg and his cronies - and all those who are its products! - realise things must change. If Facebook disappeared overnight, after a short panic, everyone would find new ways, just fine. (Hopefully some of the old ways, like email.)
Plus what @cepheus42 said a few posts above.