I’m a fan of the Capitalist Realist Shopping Cart Theory, myself.
Putting shopping carts away is bad for society and you should stop doing it.
The reason is that putting a shopping cart away requires labor, labor requires a person to do it, and the person who has to do it is employed by the grocery store.
Thus, if enough people refuse to put their shopping carts back, enough excess labor will be generated at grocery stores around the country that they will be forced to hire more people to do it, creating jobs.
I’m a fan of the Capitalist Realist Shopping Cart Theory, myself.
This is just “littering is fine because it’s someone’s job to pick it up” with extra steps.