[sudosysgen]

Well, no, because if you are an Uber driver the vast majority of the depreciation in the value of your car comes from driving Uber. Cars depreciate in large part due to mileage.

Finally, "marginal wear and tear" is a completely absurd concept. The cost of wear and tear on maintenance of a car has a positive derivative and thus has no margin, the more wear and tear the more expensive wear and tear gets. In other words, the limit of the cost of wear and tear as wear goes to infinity is divergent towards positive infinity. Thus, there is no marginal cost.

[Nydhal]

In the real world, you can't spend an infinite amount of money on a car. There is a limit. The margin will come up at some point unless the driver is completely irrational.

[sudosysgen]

Sure, but in the real world that cost is having to buy a new car, which easily increases the cost per mile by 50% and invalidates the point that "you were already driving a car".