This comes up often in discussions about Axis & Allies Online. It has an AI, but it’s pretty basic and really only there as an aid to learn the rules before playing humans. The main way the game is played is ranked play on the built in ladder against humans, or custom games. There’s a discord that runs regular tournaments as well.

The problem is AI for complex games like that is absurdly hard to develop. The combinatorial complexity of a game like Axis & Allies is something like a hundred orders of magnitude greater than chess. It’s probably similar with Civ, probably a lot more so.

But aside from just competency, what makes playing humans so compelling is personality. Human players range the full spectrum from terrible to excellent, but even beyond that they vary massively in the ways they are terrible, and the ways in which they are excellent. With A&AOL there are top tiered players that employ radically different strategies, to great effect.