Then it's not a binary system. It's a system with two extremely dominant members. Those are different things. You can be more binary in specific contexts e.g., gametes and egg vs sperm.

I'd be very cautious about the healthy description in reference to intersex people. I don't believe you are trying to say anything nefarious, but there's a reason it shows up in eugenics arguments.

I didn't say sex was a spectrum, though perhaps someone else you were speaking with did. I wouldn't use spectrum for sex, since there are multiple differentiating factors with differing measures.