Freedom of speech is one thing but when it finally translates into violent action it's a different animal.
If "defending free speech" takes us to a world where free speech doesn't exist, then you didn't actually defend free speech at all.
(You might disagree that free speech is at risk from people enacting violence against the government in an attempt to overthrow a democratic election - if so, make that argument, instead of repeating platitudes about how it's important to defend free speech you don't like.)
I’d advise you to read about:
- the paradox of tolerance https://en.wikipedia.org/wiki/Paradox_of_tolerance
- the “imminent lawless action” standard https://en.wikipedia.org/wiki/Imminent_lawless_action
If you can't allow an idea to be expressed, you are admitting that idea will overcome your ideas if it is heard. Can you really say that about the ideas that led to the Capitol fiasco? I hope not.
Lately over the last couple of decades, there has unfortunately been a new rise in fascism in Germany, due to financial crises and austerity policies. Further, the embers of fascist sympathies especially in the police and military have not been snuffed out like they should have been.
Keeping those ideas from hurting a society requires vigilance and effort, especially in history education and education of why reactionary ideas are morally and ethically reprehensible. Germany didn't try to hide away what happened or cover it up. There has always been a focus on education and telling the story of what happened, with historical references.
What was/is actually banned was the uncritical dissemination of reactionary and fascist symbols, ideas and beliefs. That's why you're not allowed to simply hang a swastika flag from your balcony, but you are very much allowed to hang it in a museum in a historical context that explains what it is, who used it and what it stood for.
That's why id Software was not allowed to distribute Wolfenstein 3-D in Germany with the original textures, because it was entertainment and not in a factual historical context.
Besides, if the best argument you have for saying something is "I have the right to say it" and not the actual content of what you're saying, maybe that says something about what you're trying to say. Ideas, not speech.
Communication, the lack of it, and the amplifying nature of that lack on social disorder is well supported relationship in modern history.
Remember, Hitler's first coup failed too.