I've always assumed and expected that machines follow rules because they do what they are told. Not because they have options and incentives.

So now a car earns for itself, why?

Maybe your car works for uber while you are not using it and returns to you, but you'd want the money for that. No human would allow a machine to earn for itself because that would lead to a machine thinking for itself and we want tools not companions. (For the most part)