To have a good discourse it totally helps if that one guy over there isn't screaming at everybody that has a slightly different opinion while he is shitting onto the table in front of the rest of us. It helps if everybody agrees what goes to far.
Federated, decentralized and free plattforms need to deal with this their own way. What if the free plattform you are hosting is used by a ring of child molestors and pedophiles? Do you accept that freedom for all also means freedom for them? Or do you enforce your own law on your own turf? While this is an extrem example, anybody who tried to run such a thing in a meaningful way had to ask themselves the same question. I am btw. aware that child molesters are a common scenario used by politicians to justify yet another crack down on encryption.
The question here is, what kind of plattform would you want to run? One where the discussions enrich the lives of a thousand people, show some of them perspectives they never had? Or rather the lawless zone where everything goes and the stronger person with the louder capslock and the meaner insults wins? Or something conspiratorial?