Yeah, that was only one case where things seemed to get out of hand too easily, but there's definitely a turning point somewhere in the middle of the exploration age where it seems like things just explode. I do as best as I can, and often am in a great place, but I struggle to have enough cash to upgrade a 4th settlement to a city in antiquity, and if you get hit with the wrong crisis, you can actually be a little bit punished and just miss out on those last few pieces.
But in exploration, just about every game I get to the point where every few turns, I can just convert a settlement to a city and buy literally every building available for it, and then rinse and repeat that every few turns. I don't want to, but otherwise I don't know what to do with things. I don't want to buy 10 missionaries every turn and have to micro them, and it's not like the 6th army commander will do me any good either.