This has been gone over so many times.
A GRC makes a man a "legal woman" but does not make them the same as biological women.
The protected characteristic of Sex mean that only those born female are protected by the characteristic of Sex.
And as I said up thread the Judge pointed out that in fact their ruling made it clear that those with a GRC could feel they had lost out.
But that is only because thanks to Stonewall etc., they never were biological females but had been led to believe they should be taken as such.
Those with a GRC have rights to change passport etc.. And not be discriminated against for being trans gender.
And just to repeat again, one of the reasons the Supreme Court ruled ie confirmed that sex means sex, is that to not do that would mean that sex would be the only protected characteristic that is undermind by another.
And yes in the past many of us have asked what it the point of a GRC. Apart from being a "win" for campaigners on gender dysphoria, it is little more than telling people you have had surgery to alter your body, or are on the "pathway" to doing that. (So far 10,000 in total in the UK)
Added to which it is now basically irrelevant as all the campaigning and shouting is about those who "self identify" - who aren't covered by any part of the law.
Although they have been taken into account by the EHRC guidelines in saying that "gender neutral" toilets should be provided.
Which you would thought that people who say they are part of that "identity" would be celebrating.
But of course aren't, as the main purpose of the campaign IS to infringe on women's sex based rights.