Ok transwomen are women. We have replaced the old sex-based meaning of "Woman" with a new, shiny better meaning based on the belief that the difference between men and women is mental not physical. Seems pretty sexist to me, but ok. For this post, I'll accept that.
Thing is, women's spaces and womens rights and so on were not set up on a whim for people of "womanly mind". They were set up as direct responses to the risks and challenges faced by people with female bodies. They were called "women's" not in anticipation that future trans women should also be included but for the very simple reason that at the time, "woman" still had the old sex based meaning and was the name for female people.
And although the meaning of "woman" may have changed since then, female bodied people do still exist. Pretty much half of humanity is female bodied and every single human that ever lived owes their existence to one of those people so it's not like we are some obscure hidden sect. And those risks and challanges we faced because of our bodies are still there even if we aren't called "women" any more.
Yes, sadly, they did not go away along with the word. They seem to be very annoyingly stuck to our bodies.
So what I do not get is why on the one hand it's all "Trans women are women, it's not about the body and you don't have to be female to be a woman" but on the other it's "Because trans women are women they need to be included in everyting set up for female people, you can't have things for female people that do not include trans women".
Seems like a contradiction there surely? Either being female-bodied is significant to being a woman, in which case trans women are not women, or being female-bodied is not sigificant to being a woman, in which case trans women don't have any claim on female-only spaces and supports and it's entirely reasonable for them to continue to exist.
Can you explain to me clearly how it works that trans women, who are not female and don't have to deal with the challenges (physical and social) of being female, are entitled to the supports for female people, but female people, who are, obviously, female and do deal with the challenges that brings, are not entitled to have female-only anything?