Yeah, I might specifically remember the US not usually having them, because they invented/popularized shopping carts, which always feels kind of backwards that they're using a simpler version.

Wikipedia has at least some info on the distribution: https://en.wikipedia.org/wiki/Shopping_cart#Deposits

(And I can confirm that here in Germany, you practically cannot find shopping carts without coin locks. I'm not sure, if I've ever seen one TBH.)

To increase your sample size, these seem to be rare where I am in western Canada. The only store I can think of that used to have them removed them at least a decade ago.

Where I live, I'd say there's on average one cart with a broken lock per corral. But they're also usually at the front of the corral, so you still end up with them relatively often...