Your “obvious truth” displays the standard ignorance around this topic. If you were intellectually curious and not pre-judging based on an emotional response you might find yourself digging in and learning the science and lived experiences of trans folks. Alas.
30 years ago people still said the same kind of uninformed stuff around gay people. Do you feel similarly about gay people?
Perhaps the commenter you are replying to hasn't, but I've looked into this extensively, listening to the lived experiences of transgender-identifying people, reading their forums, poring over the scientific research into gender dysphoria, and listening to the arguments on the gender critical side too.
From this, I can only conclude that transwomen, being of the male sex, are not actually women, but are simply men who want to be women, to the extent that they attempt to masquerade as such in everyday life.
Most of them will wear attire more typical of women, and many seem to be driven by a deep-seated sexual desire of themselves as a woman. So while it was put rather crassly, I don't see how what this commenter said was particularly inaccurate.
30 years ago people still said the same kind of uninformed stuff around gay people. Do you feel similarly about gay people?