I do it for “selfish” reasons, but not those. I want the carts in their corrals so they don’t damage my car and are in a well-known location when I want/need to use them. So, I do the work needed to make that world, and not just the minimum.

I also have to recognize that not everyone has the ability to return the cart, and so while/when I have that ability, I should return at least a few carts that aren’t “mine”.