Antifa used physical violence to confront any idea they did not like.

Silencing an opposing political opinion through violence is a definition of fascism.

Politically motivated violence is not synonymous with fascism, it's an actual political movement/"philosophy" with hallmarks and such. Plenty of violence happens in the world, both in response to speech and not, without being 'fascism'.

>Plenty of violence happens in the world, both in response to speech and not, without being 'fascism'. Politically motivated violence is not synonymous with fascism

Correct we call that terrorism when it is to further your own political, religious, social, racial, or environmental views.

Domestic terrorism: Violent, criminal acts committed by individuals and/or groups to further ideological goals stemming from domestic influences, such as those of a political, religious, social, racial, or environmental nature.

https://www.fbi.gov/investigate/terrorism

The ideas they believe they are opposing are genocide, ethnic cleansing, slavery, “women are property” levels of misogyny, and “they want our kids” levels of homophobia and transphobia.

How correct they are about what they’re fighting is a separate question. As you have demonstrated, there are many different definitions of fascism. The Berlin Wall was described as the “anti-fascism protection wall” by the DDR. And, of course, “my opponent is literally Hitler” is widely dismissed as a melodramatic overstatement.

However, if we presuppose that they are correct about who they are targeting — sadly plausible, given how many genocides followed the one in WW2 — then to say that Antifa as a movement is itself “fascist” is like saying that the Allied powers in WW2 were “fascist” for violently opposing the “political opinion” of Herr Adolf H. and Signore Benito M.