Sure, but the goal here is not necessarily to eliminate hate-speech entirely, since that is obviously impossible; the goal is to make it hard to find. You do that by not allowing hateful communities on your website. I don't want an impressionable teenager, for example, to get sucked into a fascist echo chamber on the same sites they use to talk about video games. That was (still is?) a huuuge problem in the YouTube gaming scene.
Ideally there would be systems in place to stop the fascists from creating their own echo chamber instance, but I understand why people would be scared of that power being abused. So fine, let them then. But they should never see the light of day.
Genuinely - if you do not think this is effective, how do you think we can deal with extremism effectively?