Comments on Youtube can be have been censored if the channel so wishes to do it. You can blacklist a load of words to your liking on it if you like. Youtube is also now a shitty place because of the bots demonetize everything left/right and center. Harming quite a lot of good family friendly channels at that. So bots aren't a solution and more damaging than human intervention.
This is just a problem when you start to get into the millions of people of various beliefs/thoughts and practices all being able to comment on anything they find.
There is no solution for it I think.
Also I may add who gets to define hate speech? As I see hate speech being used to refer to mere mundane of things in life being talked about.