Unfortunately, we live in a society, a world, that was not designed intelligently, it just gradually developed. Many things are remnants of things that once were useful but now are not, and some things that were never useful, but somehow just sort of stuck. One such thing involves the many arbitrary, illogical, and sometimes just plain foolish rules and customs that surround gender, identity, and roles that people are supposed to play in life. Society is an idiot, and sometimes one just has to suffer though it's drooling attempts at order and meaning. That is essentially the reason some things are so difficult, when they should not be.
Civilization evolves, just like the life that creates it.
Mistakes are made, and some things linger past their due. Inside your body is a totally useless organ, for instance. In point of fact, it is more than useless, it is actually a threat. I speak of your appendix. Attached to your intestine, the appendix is about half the size of your little finger, and it does nothing.