But a game isn't a story until it is over. RPGs generate stories by virtue of being played, but they aren't "A Story". Stories have beginnings, middles and ends. they have plots and characters, high and low points. None of that is true with RPGs except in retrospect. The story we tell about the game we just played IS the story, generated from the game. Treating an RPG like a "story" with important predestined plot points is a good way to ruin the "game" aspect and impinge on the most important element of RPG play: player agency. RPGs are games where we play to find out what happens.
(Just because the world is a weird place, I will go ahead and specifically say "all this in my opinion" as if it weren't obvious from the start.)