Gender Reassignment

I don't know why people get so hung up on trans issues (with the possible exception of competitive sports, where it's a minefield).

As we grow older, both male and female transition into a 3rd, neutral gender as the hormones become tired and no longer perform the function they did while still reproducing. Men grow breasts and women beards, both become the same basic shape. Yes, they both have different sex identifiers, but they're utterly useless, except for peeing, and even that becomes problematic.