They're usually the two spots directly next to a shopping cart chute. They allow a parent to take a returned cart from the chute and immediately put their children in it so that they don't have to walk through a parking lot where no one can see them in their rearview mirrors. Also, you may not know this, but sometimes small children just... start running when they get out of the car. If you've got more than one child, it can be very difficult to hold them while trying to get your other child or children out their carseat. Those things are like jet seats.

It's much easier to plop then in a cart that makes them visible to surrounding cars and less able to run away while unloading kids. It is also better for getting them into the store. I live in America. The average distance needed to see a 2ft child through the WINDSHIELD is shocking. When multiple cars are backing up and trying to leave a parking lot, it's not fun.

https://x.com/dannyman/status/1661087159082967040?s=20

Yes, it is "unfair" to people that don't have kids, but, given it helps reduce the chance of small children being hurt or killed, they are generally seen as a part of good parking lot design.

If you're less interested in the safety of children, perhaps you might also think about it from a profit perspective. Making accommodations for people who are interested in the safety of their children is more likely to attract people with children, who very often spend money in the store for not only themselves but also those children.

Additionally, it reduces the incidence of tragic accidents involving children in a commercial parking lot, and costs almost nothing, which is generally seen as a positive by most businesses.