Many also experience dysphoria specifically about their genitals, so it’s likely about more than just social gender constructs (probably also depends on the individual though), with at least some contributing factors already decided at birth.

I mean, ultimately everything that goes on in your mind has a neurological component of some sort. I suspect with this, for example, the brain is structured to run body template A, but is piloting body template B and is basically throwing an error. I see no reason not to change the body to match the brain, especially since modifying the brain quickly heads into major ethical concerns and philosophical weirdness. I mean, ultimately the brain is you and the body is just a meat mech.