Except that it is illegal for commercial competitors to collude to ban or restrict supply to other commercial competitors (Trump is a commercial competitor in online advertising because he buys ads, as is Parler etc etc).
This is criminal, go to gaol, cartel conduct.
I understand this side of it. I think there are several more cases going up against this too. One of the problems with not owning the infrastructure of the internet, is it being commandeered on the second-layer.