Facebook is a "Public Square"? Please. Call a spade a spade... it is a "Walled Garden". If you don't like how the roses are starting to smell, well, step outside the gates, no one is keeping you in:
Writers for broadsheet newspapers always seem to draw parallels with ye olde timey things that even their oldest readers probably haven't seen take place in decades.
That being said, the "public squares" in many big cities are almost exclusively the domain of scammers, pickpockets and the insane. So maybe the parallel does make sense.
It's a place where your family is, it's an OAuth provider depended upon by a bunch of apps, and it's hella popular as a contact page for individuals as well as businesses.
"If you don't like it, leave." is more like a religious mantra than a serious normative argument at this point. Did we mention the trackers?
The entire town is deciding to hang out in this walled garden. If I want to go to the effective town square, currently it resides within facebook's walled garden.
Personally, I just don't go, and so I miss out on the benefit I would get, but that is the price to pay at the moment.
https://www.facebook.com/help/224562897555674