Currently playing with the Smoother Difficulty mod on Demi-God difficulty, and mostly it's a ton of fun (I seem to have finally found my sweet spot in terms of not too hard, not too easy), but it's really striking how absurdly fast the AIs race up the tech and civic trees on higher difficulty settings. I'm playing with Gathering Storm which means the Ages mechanic is in play, and we've consistently been getting new ages after the smallest possible number of turns. We just officially started the Renaissance in 200 AD, and a few civs are already showing up as being in the Industrial era on the tech / civic tree display screens. At this rate, I wouldn't be surprised if a Scientific Victory became feasible some time around the historical Renaissance. And from a game play perspective, it means the game isn't quite as leisurely as I would have expected given that I set things to Marathon speed. I think it should be easy enough to change this in the XML files for my next game, but why is the game designed this way in the first place?