You would in fact be wrong, as therapy is absolutely a part of the comprehensive standard of care recommended by WPATH, and is required by practically every surgeon willing to perform any transgender related surgery.
> There is a very big difference: a homosexual person is not depressed and inhibited in functioning per sē, and this is why gender identity incongruence absent any gender dysphoria is not classified as an illness.
You’re quite close to recognizing the crucial distinction: gender dysphoria is a grouping of symptoms related to a gender incongruence, and thus itself is realistically just a poor evaluation of the condition of transgender individuals’ reality — of course they experience dysphoria, gender incongruence can do that. So we treat the problem, not a symptom. We realized that homosexuality wasn’t a mental illness because their suffering was a byproduct of society’s view of their innate sexuality, and reasonably removed the diagnosis. Likewise this will happen (and is happening) with gender dysphoria.