Emily's Cat
Rarely prone to hissy-fits
Without starting yet another sub-debate a lot of the issue is that we lump two (to me anyway) very different things under the vague term "trans."
I've always said that a biological X who defines as Y and is actively going through steps to make actual physical changes to their body; reassignment surgery, hormone treatment, etc makes absolutely 100% perfect sense because it recognizes that actual, objective, physiological changes have to be made to turn from an X into a Y.
We could quibble over whether or not it "counts" or whether or not any amount of effort really can fully change a pure X into a pure Y, but at least they are acknowledging that actual, real, objective, non-internal change has to happen.
"I'm an X but now I'm a Y and that change occurred the moment I changed my completely internal self identity and I have no intentions of making any changes beyond that and still demand to be literally thought of as a Y" is where my issue has always lay.
That's where the vast majority of the debate lies.
Although, there is still an element of the former scenario that lends itself to "in which situations do we, as a society, allow this person's medical endeavors to overshadow the material sex of others?' For someone that has completely medically transitioned, including genital reconfiguration... that ends up being almost exclusively the question of sports, where the physical advantages of a male puberty are still present. For someone who has not made cosmetic alterations to their genitals... it's a bit broader scope. Perhaps with a reasonable amount of genuine transition, we no longer care about bathrooms, or even most adult communal showers (provided they keep it covered). But we might still care a whole lot about prisons, or about middle or high school showers.

