The vegan cat thing has been a useful analogy for a few years now. No idea where it came from.
Suffragettes on the one hand I get what you mean but on the other, of course there's such a thing as a trans adult.
It's someone of one sex who wants to be perceived by society as being of the opposite sex. Some go to extensive lengths to achieve that. Some go to lesser lenths.
Trans people do exist and they deserve protections such as protection from discrimination, abuse etc etc. I draw the line at agreeing to TWAW and TMAM. They aren't. TWATW and TMATM.
(It's VERY unfortunate that Trans Women Are Trans Women leaves you with "Twat women" so it's never caught on quite).
Obviously then you go deeper into GC thinking and you end up with... well, how are they not just men? So I get that too.