> Some old houses, centuries old, are cool as a cucumber during some of the worst months of summer.
Those places also probably don't routinely hit 90% humidity levels. You sweat profusely even in the shade here (think Florida in the summer if you've ever been).
In places as hot an humid as the American south, pretty much everyone gets AC as soon as they can afford to do so. If they do not have AC, it is because they are too poor to afford it.
I'm actually kind of a hippie minimalist at heart. I'm willing to give up my car and bike everywhere. I'm willing to go vegan to save the environment. I'd even be willing to crank the AC up to 80 degrees to reduce power consumption. But I would never live in a place with no AC whatsoever, no matter how the building was built. It's one of the last luxuries I'd give up, along with daily showers.