Imagine a TCG where you can sell your collection when you want to quit the game. You could buy packs via smart contracts with full transparency wrt. card rarity. The game could add a small fee to pack prices to cover upkeep and creative costs. Some of these fees could be redistributed to players via card/pack rewards. The only requirement (and a strong one) is that the game is actually fun to play, so most of the player base isn't speculating on price.

I think this could give Hearthstone et al. a run for their money.