Aldi is the only place in the US that I know of that uses this system. It works well enough, no carts in the lot, and surprisingly people sometimes leave a quarter in the cart as a sort of “pay it forward” minor charity. (Good because not everyone keeps change these days.)
The only downside of this in the US is that homeless people will tend to hang around Aldi's asking people if they can return their cart to get the coin. Most of them are friendly and thankful but every once in awhile an aggressive person would make me very uncomfortable.
I also expect Aldi management isn't thrilled about homeless people camping outside their stores.
I can't say for the US, but over here the coin system is ubiquitous, and if you've not got a coin you can ask at the service desk and they'll hand you a branded coin to use.
