It's not semantics, it's either a deflection or a problem of defining terms. If someone says "something something antifa" you know they're talking about the disorganized association of like minded individuals who self identifies as antifa, which we seem to both agree "exists.” They didn't say "I remember the first time I met Steve Bavelacqua, Chairman of the Board of The Antifas™, he was but a young lad then." Pretending they did is disingenuous and we all know that, it just turns into this exact bullshit where someone claims, ironically semantically, that "The Antifas™" doesn't exist in an attempt to conflate it with "antifa the concept doesn't exist," which is what anyone is talking about when they say "antifa," except maybe Tucker Carlson or some shit. If you really think they're talking about an organized group ask them, if they say "no you idiot I mean the loose association of people who self identify as antifa, not my good friend Steve, owner operator of Antifa LLC," you're good, if they do mention Antifa©®LLCBBC, then correct them. Otherwise it reads as deflection, gaslighting, or denial, since you sound like you're saying the thing which we both agree, even if semantically, is "real," is not real.