I say this as someone who really likes VI, but someone who also would like them to make the gameplay simpler for the next iteration, both to help the AI and cut down on some of the busywork.
Honestly, it feels like this something games need to do in general. I mean, the motto of the industry right now seems to be "more more more" not "better," probably because that is a more objective measure (Featuring Five New Game Modes!) vs the subjective measure of making a game well balanced with a lot of depth.
I agree, Civ VI has way more mechanisms than previous iterations, and there are too many things to keep an eye on
all of them, but that's only the case when you play with the Expansions, and more when you enable the new game Modes. I think the Vanilla Game is really simple to play with, without having to look after many mechanisms of the game, and the devs did a good move with NFP to add more Civs that you can play with without the need of the expansions. But I honestly don't see why they should simplifier things just to make it easier for the AI to compete with the Human Player. You would easily get bored of the Game after some few matchs, because everything is easy and simple to play with, and the AI actions are also easily to be predicted.
I mean, just look at the new Game Modes. They can't be more Simple. Even the Industry Mode is a simple Mod made out of some few already existing Mechanisms. So what are you expecting from a Game that only adds simplified systems? Surely no challenge.
If something doesn't work as expected, you don't get used to it and act according to its limits, no, you fix it. But, you're completely right, the Devs have limited amount of resources, and especially in the current Game Industry where actions are only Investment oriented, we can not expect them making major improvements to the Game(AI) (even if they are eager to).
Nonetheless, since the Devs admitted that they built Civ VI from scratch, it's no wonder that the Game isn't well balanced, especially because they didn't knew from the beginning how the Game would evolve, and the expansions weren't planned thoroughly so they could be balanced and play smouthly with each other. I really hope that they're going with Civ VI as the Base for Civ 7, so they can build on it, and that Civ 7 AI would be an enhanced/improved AI of Civ VI. Otherwise we would just get a Civ 6.5, just with a new Appearance. And that's why I think Civ 6 was never intended to be a completed Game or the better version of combined previous iterations, but just a build up for Civ 7 (At least since NFP we have the complete Impression that it's just a test base for new content/mechanisms), so the Latter can be what Civ 6 was/is anticipated to be but never intended for, a Combination of successful Mechanisms from previous iterations but with way more depth and capacity.