This is the function of that grocery cart loop
From time to time, you load a grocery cart with a lot of stuff only to discover that some of the fragile objects have broken. The grocery cart loop is usually placed on the back of the children’s seat, and while you might have thought it was some kind of design, it actually has a very practical use that most people are unaware of.
Many carts include loops on the sides where you can hang bags. Those without side loops usually have a few at the handle where the child seat is located. This elevates your fragile items above the rest of your belongings, preventing them from being smashed or crushed. To sum up, the loops are there to protect your fragile groceries. It seems brilliant.