I mean I’m in agreement that “gender” as a term has very little bearing on physical human beings, as we are a dimorphic sexual species.

However I don’t understand your argument because this is my point; no one agrees on what to call it. Call it whatever you like. Whatever it is and whatever it does do, what it categorically does not do is make a male body into a female body.

So in my opinion it does not change sex, it does not reassign it, because I don’t believe “sex” is merely the state of someone’s genitals or their hormone levels.

Edit: Hence I oppose the language, not like willing to die on a hill for it but just generally I think the notion is disagreeable.