I think to just brush over surgery fixing a malloclusion as "cosmetic" as if it's kind of a trite thing just doesnt seem right. There's definitely risks since there's a lot of nerves that can get botched in jaw surgeries causing different problems.

I can tell you tho I would never consider it just so superficial. A lot of unconscious behavior happens based on facial symmetry that is hard wired into us. Malloclusions can effect breathing especially at night (some problems that will only surface later in life when options to fix limited by your age), the way other parts of your face look such as the nose, oral health, long term root problems, uneven wear etc etc

I had a doctor that just shrugged his shoulders and said the same thing to me. I wish id had a doctor that pressed me a little to really think about the long term picture when I had the chance.

If theres already problems like pain etc then obviously the justification is more than cosmetic.

I dont know if you are still young enough I would reconsider. I think in general overbites are still more bearable than under.