It seems that Harry is more powerful in comparison to Dumbledore - as Dumbledore had fought and defeated Gellert Grindelwald with much difficulty, and he was afraid to fight Voldemort, as Voldemort had some powers which he could only dream of. But Harry defeated Voldemort. So, Harry should be on the top of the list of the most powerful wizards. Do you agree?
I see what you're saying, but Harry's triumph against Voldemort wasn't really a fair duel (we've seen before that Voldemort absolutely wrecks Harry in a typical fight); Harry "won" because of the Elder Wand (and plot armor).
Remember, Harry was easily beaten by Snape, who (as skilled as he was) couldn't compare to Voldemort.
Updated on March 21, 2018
By Jeremy Gill