Why doesn't the shopping cart in the supermarket run around on the elevator, but it is tightly sucked on the elevator surface?

Shopping cart wheels in supermarkets have two hard narrow edges that can roll. Usually, it is no problem for this narrow edge to roll on smooth ground. The floor of the elevator conveyor belt is alternately composed of strips and aluminum alloy protrusions. Once the wheels of this shopping cart reach the elevator, the rolling narrow edge will sink into the gap, and the protrusions on the floor will hold against the fixed parts of the wheels, making the car unable to move.