Gametes are binary.
It's just that by the time you are looking at the level of sex there are so many ways for things to get a bit mixed up that it is no longer binary. It's like you can combine 32 binary bits to make a single precision floating point value. Nobody will claim the floating point value is binary.
Sexual
characteristics are not necessarily binary, but sex is functionally binary in mammals and disorders of sexual development do not change that.
However, as I've said before,
the intersex gambit is a furphy. The trans activist movement is not an intersex awareness movement. The trans activist movement's religious chant is "trans women are women", not "some people have disorders of sexual development and therefore some people who were identified male at birth might be closer to biologically female than you think".
No. The trans movement does
not make the claim that males who produce sperm, have male-typical gonads, are XY, and have normal amounts of testosterone in their system do not get to be trans women. Nor does the trans movement even want males to have to take
any measures whatsoever in order for trans-identified males to be treated socially and legally as women.
Sex in mammals is binary. Gender can be anything at all, because gender identity is a thought in a person's head. I have never inquired about somebody's 'gender' because I don't give a shit and I have no obligation to honour somebody's "gender", whatever that would mean.
I can see whether you are male or female. Volunteering your "gender identity" is like telling me you are a Pisces.