I'm from Colombia, the Caribbean region to be more exactly, and it's obviously common there (if you're middle class and upwards, and can afford the rise on the energy bill), but in other not so warm cities you barely see them. I'm currently living in Chile and I've yet to see an AC in an apartment/house.
That said AC at reasonable levels is wonderful.
This year (last week) I bought a second one to put in the bedroom and set it up for the night. That breeze was really refreshing.
However I feel that this year people are buying the Portable AC units a lot more (there’s no stock left for moderately priced portable units on Amazon at the moment). I’ve lived in Delhi most of my life so I can survive 33 degrees in Paris, but our cat doesn’t seem to enjoy it.
But malls, offices and the like have AC.
I've never been in South America, but I'd say that the average weather conditions in France (less heat and humidity) makes AC less important.
Lots of neighbors have AC running but all the windows and doors wide open.
Edit: I live in an pre-Haussmann flat (5th floor, right under the roof). Crazy hot but no AC and no fan, all the windows open since Monday, days and night, even when I'm not at home. Crossing fingers re possible theft, but at least no one can steal my non-existent AC).