Schultz, let's follow this through logically.
A male-bodied person believes they are a woman. No problem for anyone else and no business of theirs, either.
That person signs up for surgery (though most MtoF don't, in fact) and begins to present as a woman - clothes, hair, makeup, the externals.
They now feel uncomfortable, even unsafe, using the Gents' because they fear negative reactions, even violence, from other men.
They want to use the Ladies' because no men are allowed in there, making it a safe, single-sex space.
The moment anyone can self ID and people are told they are free to use the facilities that they feel match their gender identity, the door has been kicked open, predatory men are free to walk in alongside the MtoF individuals, cannot be challenged and can do their worst.
So the safe, single-sex space that women resorted to and MtoF coveted is lost to all and everybody who needed or wanted to access it.
Do you see?
Women are no longer safe there. MtoF people are not safe there either. Nobody is safe anywhere any longer. Safety is compromised and everyone is looking over their shoulder.
Unless of course you naïvely trust that no predatory man would ever dream of abusing the golden opportunity the TRAs have handed him, in which case you are living in cloud-cuckoo-land. Predatory men will scarcely be able to believe their luck, or credit how stupid everyone is being in making it easy for them to exploit gender ideology.
You can say it would never happen all you like, but of course it already has, and can only get worse. At least someone might have spotted a man going into the Ladies' and reported it for security to check out, perhaps averting a sexual assault or worse. But in future, nobody will blink an eye, security will shrug and say it's legal and women, girls and MtoF people will be left vulnerable.
It's not about letting transwomen into single-sex spaces, is it? It's about who follows them in when the sign on the door has been changed to "All Comers".
Please tell me you have followed the logic.
If predatory men are honestly not a problem and never have been, why are MtoF people clamouring to use women's single-sex spaces in the first place?