Comment by programd

You could mod the game with more varied events, which were of course AI generated to begin with. Bit of an inception scenario where AI plays an AI modded game.

The other option is to have an AI play another AI which is working as an antagonist, trying to make the player fail. More global plagues! More scheming underlings! More questionable choices for relaxation! Bit of an arms race there.

Honestly I prefer Crusader Kings II if for no other reason that the UI is just so brilliantly insanely obtuse while also being very good looking.