Toilets and other single sex spaces are rarely subject to inspection on entry, which is why men keep telling us they’re going to keep using women’s spaces and also make specious claims about genital inspection.
The reality is that women complain if men are present in their spaces. If they complain fast, and the men are (mal)lingering, that might result in an unceremonious marching out by security.
If it’s in the workspace or a business providing services, the management are obliged to deal with it. May not be easy, but undoubtedly there are means.
Women are not likely to complain about something normal like other people’s children of a suitable age.
So there’s the difference. Though policing is rarely needed, single sex spaces generally operate on trust and consensus. The SC ruling now makes it clear that women have the right to complain about the men they don’t want in their spaces.
It is not going to create a situation where everyone sticks rigidly to boundaries based on sex. Women will ask for the men they want ejected to be removed. We don’t care about seven year old boys and are not going to start objecting to them any time soon.