Yes, everyone is unique to some degree. For instance my wife’s uterus is slightly tilted. It rarely matters, but every once in a while it causes discomfort. Knowing this, doctors don’t need to over react to additional and unexpected discomfort during pregnancy. But this isn’t relevant most of the time, so hospitals focus on factors that help quickly and efficiently diagnose the issue. Age and sex are probably the biggest of these factors, along with medical history. Gender identity is usually not important, though in some cases it could help identify someone who is intersex. But these cases are rare enough not to warrant their own check box, much like a tilted uterus.

Maybe I’m not understanding your comment, but in certain contexts, gender identity is not relevant but biological sex IS, such as in treatment or early diagnosis of cancers that are specific to one sex or the other. Hospitals need to be able to communicate verbally and in email or written correspondence about these things, but if language is obfuscated to the point where it is not clear what that individual’s risks are (based on their sex), then it is only that individual who will be worse off for it. This point doesn’t need to be extrapolated to larger contexts for political power, but it should also not be ignored because of possible implications to larger gender identity questions.