Did anyone ever truly deny there are “biological” genders? I don’t think they did, or do. It was always trying to find the right way to balance competing needs. Something the Supreme Court judgement hasn’t done, because it wasn’t asked to.
“Biological” women now have the security of knowing that the toilets, changing rooms, etc they use will not be used by “biological” men. Which solves one problem but creates another.
“Biological” men who identify, dress and behave as women must now use male facilities or search for shared ones. Which aren’t yet widely available. I think should they use male facilities they would be at much greater risk than a “biological” women would be if they used female facilities.
The consequence of which will undoubtedly be a move to shared facilities. Something that has already started but will add cost and take time. Whilst in Germany recently I saw the ideal solution to the toilet issue. Shared facilities, with a single entrance, charged for by card entry. A area of male only urinals, screened from view by others, and another of closets and wash hand basins open to all. No one seemed discomforted in any way using them.