Same with Los Angeles. In the 1950s, when my parents were young, you didn't need AC in LA. You just opened a window on the few hot days, and those were like high 70s/low 80s.

By the 1990s, you didn't need AC, but your home/rental was more appealing if it had one, because there were a few hot days a year that were pretty uncomfortable otherwise.

Now, you can't not have it. There are far too many hot days to live without it.