It was never about skill. Harry was never a greatly skilled wizard, he would never have beaten Voldy or any death eater really, would he have to duel them in fair fights. He was an average wizard (even compared with his classmates) with limited skills (expelliarmus and expecto patronum were about the only charms he was remarkably good about, none of wich could harm or kill -which tells us something about him, BTW).
The whole point in that Voldy was killed by his own fear of death, which brought him to do foolish choices. He basically signed his death warrant the day he chose to act on the prophecy. It's all explained in the books.
I loved his death because he was killed exactly like the first time seven years ago, by his own curse, which show that the most greatly skilled wizard never ever learned a thing (or at least the only thing that mattered), he his the only character to never evolves, it's poetic justice. It's fit for him. Great death.