He did heroic things, saved the day but anyone else think he didn't fullfill his potential and could have become a great wizard like Dumbledore, Riddle?

 

Nope, he didn't come even close, dude could be the next great Grand Kahuna of the wizarding world if he had put his mind to study even a bit of the fascinating thing that is magic. (And more fascinating to him because it was literally his get-away-from-hell ticket and, let's be real here, why the fuck a child created by muggles would be happy to be just lazying around, eating and playing chess instead of being at least a bit interested in magic?)

But Harry was just so happy learning some bits of magic here and there and using expelliarmus against a murderous magical warhead with legs and a bad temper and winning the war by factor of Dumbledore Ex-Machina, so there's that.