Easier or more difficult to get by without shouldn't distract us from the core point GP made, that corporate (arbitrary) censorship, with no redress, should be taken as seriously as govt censorship. These days they are just two arms on the same chimera.
The answer is: groups of people (and corporations are groups of people) are free to limit speech according to whatever rules the group decides upon. What you're proposing is that certain large corporations be treated as quasi-governmental entities. Which is a _free-speech restriction_.
Not saying it's a bad idea, necessarily. But I'd rather my freedom to say that certain types of speech are unacceptable was guaranteed.
My point is censorship is a huge responsibility and power, especially when it is done at the scale govts and multi-national corps do, and therefore it needs serious transparency and checks and balances, in both cases.
I don't see this happening to satisfaction. Instances of regrettable censorship stay regrettable, and keep recurring.
I just can't quite go as far as to say that Google or Facebook should be treated as governmental entities. The bill of rights restricts what government can do. It has never been interpreted as restricting what an individual person can do, even if that person heads a giant corporation.
Solve these problems another way, not by literally nationalizing social media.