You mean like decentralized antifa groups so nebulous and obfuscated that they have their own website, wikipedia entry, and twitter page, like Rose City Antifa?
https://en.wikipedia.org/wiki/Rose_City_Antifa
https://rosecityantifa.org/
Listen, I understand the argument you are making. It just looks really disingenuous because I experience the "fight against fascism" locally on a daily basis, and many of these Antifa groups are so brazen that they are completely open in the public about what they do.
It seems like you're making the argument "cant identify antifa because they wear masks, and like, how could you prove it" when these groups literally recruit on my local craigslist