"It is worth noting that it is at least almost always comorbid with depression and anxiety, and transitioning does not alleviate those symptoms."
Actually, it does, to varying degrees. And yes, surgical intervention for a mental disorder seems weird, but it's the best "cure" we have. People with gender dysphoria do not "grow out of it", and the incidence of regret for sex reassignment surgery is low. Very low. 0.1% or so, and to put that into perspective, that is 1/10th of the incidence of regret for knee surgery. At least it was before they started offering the surgery to people not diagnosed with gender dysphoria (and that is a condition almost impossible to accurately diagnose in children and adolescents, for instance)
The depression and anxiety often remain not because of disappointment after the transition, nor other internal issues, but by the acceptance (or lack of it) of transgenders by society. Thankfully that has improved by leaps and bounds: 30 years ago it was unheard of, 20 years ago it was awkward, 10 years ago something to be curious about. These days people hardly bat an eyelid.