AI-generated maps and NPCs might be ok. Ditto fights, though there would have to be playtesters whose job it is to make sure the result is something winnable and acceptably fair.

The main issue there would be that there IS no continual certainty of that. You'd have to either be able to rerolled entire encounters — which would be jarring — or force the AI to DM what happens when you lose an impossible battle — far more rewarding, provided it doesn't keep doing it. But it may keep doing it. This would be impossible to ever test adequately. Every game on the market may be a hard mode Bethesda game.

I personally really don't think I'd enjoy something with a randomly generated cast/main story for the same reason I wouldn't be interested in owning one singular book whose writing changes every time you read it. I don't play to kill time; I play for the stories and I get attached like hell to the good ones. I replay them ad nauseam because I miss the characters.

I think it would be an intensely entertaining idea either as a New Game+ or for those games to have a wildcard setting that you could turn on and off. That way, there's no lack of devs who get to tell the tale they wanted and players can mix it up when they're bored. Otherwise, you've downgraded the job of the entire company to filling the AI in on background lore and nothing else.

Other aspects:

• for those that do get attached and wanna re-experience it, you'd need a way to save the information behind the game you just played. That file might be fairly gigantic?

• Would also lead to a weird market for other peoples' saves. The way modders already make quests, but for an entire plot.

• NPCs and party members that all look like randomized sims.