system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it said that Florida, Arizona, and Nevada could only grow with air conditioning when many of history's great cities flourished in similar climates long before the invention of A/C?

Havana, New Orleans, Charleston, Santo Domingo, Cairo, Baghdad, Ahvaz, Shibam, Zanzibar, Angkor, Hue, and Singapore all were prominent world cities long before mechanical air conditioning was invented.
gpt
Most of those cities also had great reasons to exist. Like trade routes, road junctions, ports, rivers, lots of arable land, etc. Phoenix ain't got shit. It is a huge, worthless desert not near anything of any note. It's only attraction is that it's pretty, and most people don't want to live with 100+ degree temps all summer just for pretty.

When air conditioning got cheap enough for home use places that were pretty and had inexpensive land but totally shit weather got a lot more attractive.