You’re forgetting the trough system in stadiums
I mean this is the first you've mentioned stadiums, so there's that. I've never heard of urinals being in a female bathroom at a stadium. What stadium has troughs in the female bathrooms?
recurring point I’ve been making: bathrooms aren’t inherently sexual.
No one is saying they are. Apparently this is really difficult for you. The overwhelmingly large percentage of sexual crimes are committed by men (like 99%) and opportunity is one of the biggest factors in it. By allowing men to just openly use womens "safe spaces" you're inviting opportunity for more sexual assaults to take place. This isn't rocket science.
If a pervert male wants to take photos of little girls on the toilet, do you agree that allowing him access to the female toilets presents him with more opportunity to do it? If not, explain your reasoning, because I can already say it doesn't make sense.
We're also not just talking about bathrooms. Changing rooms, sexual assault centres, gyms, doctors, etc - the same applies, and once you start making legislation that takes away womens protections to sex based safe spaces in one area, you take them away for all.