Alternatively, we could just have coed communal bathrooms everyone uses, everyone uses a stall, everyone washes their hands in the same line. Fathers of daughters might be upset, but they could go in with them.

Seattle has done this in a few places! The city just redid a park along the downtown waterfront, and put in a big communal bathroom, and I’ve seen a couple at the SeaTac airport too. Maybe I’m a bit biased as a trans woman, but it really seems like the best solution to me.