And yet, lots of people in pre-Musk times said "Twitter is not a government body, it's a private company, it can ban whoever it wants to ban". Now these people are leaving in droves.

I hope it's a good lesson for everybody that a private company can't be a de facto town square. An internet town square must be based on open protocols and, like an IRL town square, paid with taxpayers money. Otherwise, we're doomed to have this story repeated again and again.