The sex/gender distinction of the 20th century and now deeply popular among LGBT+ circles in the 21st century was one step forwards, two steps backwards. Although it provides a simple "explanation" of trans people, it ultimately cements sex and thus patriarchy as the natural state of things. Human sex has always been a social concept with biological justifications applied retroactively and selectively. The proletarianization of women and advances in medical science lay bare the absurdity of sex and for the first time in human history create the conditions for the world-historical abolition of sex and male supremacy. As the proletarian revolution self-abolishes the proletariat, so too does the transsexual-feminist social revolution self-abolish the woman and transsexual. Down with cisgenderism!
It may be linguistically redundant, but it still establishes a point that a lot of people seem to forget about assigned sex at birth: that it is coercive and rooted in social construction. The point is that, with a lot of people allowing "AMAB/AFAB" essentialism to take the gender binary's place (because they are functionally the same thing, whether AGAB essentialists will admit it or not), we need to remember that "AMAB" and "AFAB" have way less important meaning than people give it. We're now at a point where I've legitimately seen people say things like "I support AFAB rights!" and it's honestly disgusting.
That just seems like terf shit, and I feel like disgusting people will find a way to be disgusting no matter what terms we use. But I see your point, thanks for expounding.
Yeah, I'm not a fan of using terms like "CAxAB" either, but I get where it comes from. I don't want any kind of gender essentialism at all actually, and it honestly would become a euphemism treadmill if we keep replacing terms. For instance, "AMAB" and "AFAB" have become what "biologically male" and "biologically female" are, and if "CAMAB" and "CAFAB" came into regular usage, the same exact shit would happen with that term.