If in UK, ladies changing rooms in swimming pools and gyms are open, why are men allowed in if they say they are a woman?

I was out shopping yesterday in a well known chain store. They have separate mens and womens changing rooms.....but.....the ladies now says outside 'female and any gender' changing rooms and the first section of about 6 cubicles state 'any gender' on the curtain.

I thought it odd.....as 'any gender' implies men can go in those too......yet they have separate mens facilities.......

I think with the Supreme Court's recent judgement that is no longer true.

Shoreditch in london has unisex toilets.
Theres no difference in them and having trans accepted
As far as law goes no they arent able to use toilets which differentiate from their biological sex.

Simple: they're not.

Why does anyone care? What does it matter. It isn't like it serves any purpose to have separate changing rooms anyway. Reguardless of gender or sex you're going into the room and closing and locking the door behind you anyway.