Trisher your post is so flawed. Transwomen pose the same risk to women as men do, because thats what they are!
Female, properly female killers are so rare that they become household names, but men kill women and other men with such frequency that its often barely news, and sometimes isnt even reported on beyond the court round ups
But its not just major crimes, there is in built mysogyny even in "nice guys" which transwomen activists demonstrate on a regular basis.
Do you swim? I swim. I swim well so I lane swim. Women make themselves small, keep out of the way, men spread out making women have to make themselves small. Not all women at ladies only swim slots are conservative/religous/neurotic, some just want a break from making themselves small when men physically dominate lanes because its exhausting.
Your post is like saying why bother with distinguished cycle lanes you might as well cycle down the middle of a motorway cause sometimes some accidents happen on cycle lanes too.
The other point to remember is that for people who need same sex police officers or nurses or doctors or social workers, they wont request one in advance if they hear all female names/pronouns when they ask who they'll be seeing. And may not have the confidence to do so on the spot when someone clearly male books in.
M&S has a transwoman bra fitter, if you book in now you wont know in advance if you (or your nervous shy 14 year old) will be getting a male or female fitter unless you know that transwomans first name. And if you ask the staff you book with if your fitter will be female, they will say "yes" either way