I’ve been designing/coding games since I was 11yo and have a degree in gamedesign & dev. The hardest part isn’t the technical side of the game’s AI. It’s finding the balance of an AI that makes the gamer feel powerful enough to be fun- but not too powerful to become bored - and not find it too hard that he/she becomes demotivated. Obviously every player is different so finding a balance that can keep the gamer excited enough to continue is extremely hard. Getting the emotional-experience side of the player into the sweet zone is hard. One would say ‘why not make the AI such that it adapts to the user’. Which is 50% of the answer. But the challenge then becomes that you don’t want good players to be at the same level as bad players when the AI creates a similar experience for both. You want both players to enjoy the game, but not in the same way.