There was a study a while back that suggested that reddit's banning of hate groups really did reduce the amount of hate on reddit. That is: GreatApes didn't go and infect other subreddits, and there was a real reduction in the hate on reddit.

That doesn't mean that everyone didn't go off to voat or whatever, but then they have to rely on voat for growth, and can't piggyback on reddit's MAUs.