Comments from being a teacher in various schools:
The boys toilet absolutely stink when they open the door - that stink will be carried out into the corridors.
The boys are more likely to wee on the floor and seat of the toilet cubicles at secondary school. Maybe this will improve because I am sure this doesn’t happen at home.
The boys will bang on the doors of the female cubicles. This has happened to me as a teacher in the disabled loo - they laughed as they heard a crinkly tampon wrapper - got the shock of their lives when I stormed out.
When girls are being harassed by boys, the toilets are safe area. This I have close experience of.
I have helped young girls clean period stains off their skirts and trousers using the sinks and hand dryers in the girls loos.
There will be all sorts of stuff in those sanitary bins. And it’s not nice to sit down next to a sanitary bin brushing your thigh, whatever sex you are.
Gangs congregate round the loos. That will still happen. The sink areas will be a major preening area for the alpha females, putting the boys off or a flirting area (splashing water etc) for both, with the alpha males going for vapes in the loos. Either will put off others going to the loo.
The only way it could work is if there are separate traditional toilet facilities for girls and boys too.