The supermarkets here use technology. The wheels have a locking device that, once the carts get to a certain point in the parking lot, the wheels lock up. Now, back in the day, yes, there were carts left all over the place. Once in a while, you will see a homeless person using one, but not that often.
It could also be a neighborhood thing. Around here, you just need the cart to get you to the trunk of your car. In many cases, the supermarket has people that will push the cart for you and give you a hand putting the items in your car.