I guess you could argue Facebook should be shutdown as parlor was. Although parlor was only used for hate, Facebook didn't do anything to stop it either. I think a big issue is how facebooks algo (and others) are built for maximum profit which at the same time also radicalizes people in their filter bubble.
I think Facebook should be broken up but I havent heard any good ideas yet regarding how to somehow regulate social networks. Beyond hate speech, I dont see any reason to limit what people can say. Somehow limiting how the network connects people, or how content propagates, seems like the key. Only FB has done the social experiments at scale to know how to engineer this, which is faintly ironic.
They are free to run algos to auto reject, sort whatever order.
This would likely be too burdensome, and the socials would almost certainly have to start charging for access, which in of itself would probably remove much of the problem.