Quirrell, chapter 65:

“You are kidnapped from Hogwartss to public location, many witnesssess, wardss keep out protectorss. Dark Lord announcess that he hass at long lasst regained physical form, after wandering as sspirit for yearss; ssayss that he hass gained sstill greater power, not even you can sstop him now. Offerss to let you duel. You casst guardian Charm, Dark Lord laughss at you, ssayss he iss not life-eater. Casstss Killing Cursse at you, you block, watcherss ssee Dark Lord explode -"

With Dumbledore out of the way, Harry becomes the unrivaled leader of the light side, which could make him quasi-king of magical Britain with some maneuvring. His power only increases as he gets older. Voldemort!Riddle enjoys watching Harry!Riddle do all the work, while he goes on a multi-decade vacation on a nice beach in the Caribbean.

The End.