The point isn’t getting rid of all of them, the point is making it so people who are toxic require putting in additional effort.
You make it harder and many people who would be toxic for whatever reason will eventually “give up” because it takes to much effort.
There will also be some level of toxic/trolling/et cetera players. But if you punish people for it, you will make that a much smaller amount than if you do nothing because nothing can be done.
Like in my work, certain things are secured. That security won’t do much if a thief who plans things out wants to steal them. BUT if someone who is an opportunistic thief is there, the extra effort will deter them. And I’ve seen this work in real life multiple times. Doing things that DO NOT STOP the problem but deter the majority of people who would steal works.
The same applies here, for the most part.