Having recently considered playing Dwarf Fortress(and quickly rejecting it for UI issues and overall tediousness), it seemed like a game that would benefit from an LLM backend. I'm curious what sorts of world history an LLM could come up with. It likely would be a lot less efficient than the current system, but interesting nonetheless. I think it would be easy for devs/modders to add a way to supply an API key to an LLM and experiment there.
Also having recently played a run of Civ5(before burning out because the late game is tedious and the overall game so unrealistic), I thought that good AI would help 4x games remain epic while letting the user choose their level of tedium. It would be nice, for instance, to manually go through the early game when management is easy and exploration is fun, only to turn that over to an AI at some point(and you generally do with autoexploration). Same thing with other eras though. By the time I'm in the late game and have a large empire, I'd rather focus on diplomacy and moving armies, not city management or worker management. I don't want to commit to fully giving up on those aspects of the game though. It would be nice to, say, automate war mostly but be able to jump in if I want to micromanage for a few turns.
Distant Worlds I and now II has had full automation for ages.