In RPG’s whether it is on the table top or on the screen, story is the context of the game.
It isn’t the game itself, it is the context for the game. It is what allows the game to make sense to the players.
Why are we going into this subterranean maze full of traps and monsters? Oh, a legendary sword was stolen and the thief who had it was part of an adventuring party that went in here and never came out. I guess that’s worth the risk.
Why is this forest so infested with monsters? The chaos gods sent a curse as punishment to a warrior that betrayed them. Makes sense.