To use one current example: The people pushing the idea of trans people as "groomers" is violence. It is not an intellectual debate, it's not necessary to entertain in order to preserve free thought, etc.
The goal of that speech is to other trans people and it endangers them. Tolerance of that kind of speech ensures that trans people cannot participate equally in society when there's no consequences for trying to stoke hate and encourage stochastic terrorism.
At some point, if we cannot agree that things like that are unacceptable I don't see how we ever move forward.