And if someone wearing a dress walks into the men’s room, uses a stall, washes their hands, and leaves, who are you, or I, or anyone else, to challenge them?
Why should that be a problem?
What a lot of posters won’t admit is that someone wearing a dress in a men’s bathroom would be more likely to be subjected to some form of harassment, if not violence than someone who had a male appearance and was wearing a typical male wardrobe. Regardless of what is under the clothing of the person in a skirt or the person in a pair of pants.
Sure, I wish that everybody felt free and comfortable with their bodies and other people’s bodies but the fact is that people have different needs for modesty and some of those needs are dependent upon developmental stage. Few women would be upset at a little boy in the women’s bathroom or shower room. They’d be more upset at a 16 year old boy in the same space. Even the most open woman would likely prefer more privacy if they were menstruating, recovering from childbirth, had had a mastectomy, for some examples.
Children are less likely to be upset at the sight of a naked adult ( unless this is forbidden in their home) compared with an adolescent.