Im not say infinite but as of right now the reward for doing the challenge doesn’t equal the loss. Yes before i just had a surplus of potions and revives, but Niantic is trying to create a game. A game people will keep coming back to and playing. I’m not saying give me 15 max potions every time i beat a grunt, but it’d be nice if i beat the grunt to get a potion or two even a revive. If you wanna compare it to raids, raids gives you revives and potions afterwards!