Being a man or a woman is more than just your biological makeup. It makes a very significant difference in what behavior people expect from you and how they interpret what you do. In other words, there's very much a sense in which men are those who get seen and treated as men.

And personally, I see no reason why having male genitals is necessary for getting seen and treated as a man. If you behave like you want to get seen and treated as a man, I'll see and treat you like a man. The only people who have a remote interest in the actual biological makeup underlying that behavior are people who are romantically involved or interested. Oh, and medical personnel.