It IS important to stop fascist speech because fascist speech is fascist recruitment. That is why anti will fight to deny any fascist a platform.
I recently read a book about anti-fascism What Is Fascism? An Excerpt From “Fascism Today: What It Is and How to End It” | Truthout and it’s very enlightening to read the theory. Highly recommend. These folks have battled fascism for a 100 years and laws and governments are rarely any help. There is “liberal antifa” and for example sued the KKK out of existence and it includes using laws to sue fascists like Rowlings and Musk.
Otherwise there are only the streets.
So how should a civilized society deal with vile speech amplified and magnified that works to bringing and end to civilized society?