AI in games is not AI in the CS sense, and that’s probably where the confusion is coming from. AI in games uses the cultural definition that includes things like C3PO and whatnot, whereas AI in the CS sense is just about any algorithm that seems to learn as its environment changes, usually to find a better (more fitting) solution than the previous iteration. Game AI is generally just pathing and direct responses to stimuli, it doesn’t really learn, so players can cheese the AI pretty consistently.

I think games using actual AI would be undesirable because it would make games involving AI much less predictable and probably way harder. It would also likely use way more compute resources.