1. Make a game that changes difficulty based on player skill. Good players would be rewarded by the game getting even harder.1. That's not a reward, that's a punishment. Physcologically players would need a narrative built around that or other rewards to make it work.
2. Make a game that rewards player for using as many consumable items as possible. Perhaps replenishing their entire stock and getting a few bonus items after ever battle.
2. Then at that point, they aren't consumables. They're more like spells with a recharge time.