I understand that it's hard to code proper AI, and it also might not be worth over-investing into it prior to 1.0.
Still, from the bits and pieces that I'm hearing, it appears like AI so far is just bad. I hear that coalitions can be bought off cheaply, and it just doesn't know how to play well.
To me, good AI that is actually a challenger and not just a scarecrow is half of what makes the game good. And 95+% of us play only single player. Especially in these times of AI hype and bubble, I would really expect there to be significant leaps in how smart AI is - especially in a game that is essentially runs on turns. I don't really expect it to be a strategic mastermind, but I do expect some basic awareness and forward thinking.
I don't want "hard" AI to be hard because they are printing money out of thin air and have a ton of modifiers, I would want it to be hard because they actually seek good economy and military and are impossible to abuse.