Recently in NL many supermarkets have dropped the coin completely. But people have been conditioned for years to return the cart. Though there are cart thieves.
In the UK some places have it, some do not. Lidl does need the coin, Waitrose does not but has a system that stops you taking them out beyond the car park (there are warnings on, other supermarkets do not.
Almost everyone returns them in all the supermarkets in my area.
My elderly mom never shops at Aldi (in the US) because she can't figure out the coin thing. Given that she spends outrageous amounts on groceries, Aldi is losing a ton of money by paywalling the stupid cart.
