I'm not entirely sure what his reward could be... whatever evil demon took his soul and tied it to the game probably won't just undo his contract on a whim.
He might have to log in every day for the rest of his life if he wants to stay alive. Revenge in a video game is bitter sweet, like yeah you got your one up on the douche bag but at the end of the day it's just a game.
People who take games too seriously might feel like this is justified but at least there's monetary gain here in these games... so he could be rich but still have to game forever to stay on life support.
The douchebag literally loses nothing even if he is defeated in game because the game is just a side hobby for him. He's a goddamn wealthy heir, super model and actor for christ sake. 😅
For the mc, this whole game is his life, for the "douchebag antagonist" this is his Tuesday night for like two hours tops. 😆
The fact that this is a game makes all of the achievements of the mc arbitrary, but also diminishes the action and stakes. Again, only the mc is at risk in every endeavor, and because he's the main character, that means every obstacle he faces will be over come no matter what because if he dies in the game he will die in real life.
Tldr; once you turn back on your brain, the story is actually objectively bad 😅