How is this happening? Why aren’t companies etc. adhering to the equalities act?

So they had to put in exceptions to say when that was permitted.
But it never occurred to them to say they were required, and that wouldn't have been part of "equality" anyway.

But surely where a company has separate women’s and men’s (say) toilets, they have invoked this exception.

If they then allow transwomen into the ladies’, aren’t they then revoking the exception, making it now discriminatory not to let the other men in?

why are there people with penises in women’s prisons? Why are retailers saying use the changing rooms you identify with? etc.

… because Stonewall got its dirty little fingers everywhere, and told everyone they were breaking the law and being bigoted. Recently there has been a little sunlight on some of this, and people are starting to realise the truth.

There's been such a huge effort to give the impression that single sex services can never be justified without a court precedent, the result is providers don't take the risk.

The acceptable risk is discrimination against women, not trans.

But if that’s the case, why are there people with penises in women’s prisons? Why are retailers saying use the changing rooms you identify with? etc.

Short answer is that that wasn't really the remit of the Equality Act.

The equality act was about preventing discrimination.

So stuff like you're talking about only came up in it as examples of permitted discrimination. A straight "equality act" would have barred single-sex spaces as sex discrimination. So they had to put in exceptions to say when that was permitted.

But it never occurred to them to say they were required, and that wouldn't have been part of "equality" anyway.

The most the EA2010 can help you is with a possible argument about indirect discrimination - providing only mixed-sex services could be said to harm women more then men, thus indirect sex discrimination.

There are some other laws and regulations requiring split-sex provisions, but they're not the EA2010.

Basically split-sex provision was so obvious that there's never really been much need to legislation to require it. Much as there's not much scientific literature stating that humans come in two sexes.

I don't get it either, we should be dividing on sex not gender.
No point saying we have single sex wards if that is being over ruled by gender which can be fluid!