Either they are publishers (like newspapers and thereby have editors and control content) or they are platforms (they are just a place where anybody can post comments nd there is no editor and the platform bears no responsibility for content(.
Twitter, Facebook etc like the freedom of being platforms and the freedom to allow people freely comment, but they add a layer of editing. They ban people they don’t agree with, remove or shadow ban content to limit people reaching their audiences.
They can’t have it both ways.