The time you spend in your car is more valuable than the cost of the car itself (including gas, repairs, etc). So insofar as you can free that time with an auto

The time you spend in your car is more valuable than the cost of the car itself (including gas, repairs, etc). So insofar as you can free that time with an autonomous vehicle, it can absolutely slash the total cost of transportation. To a lesser extent, similar things can be said about your other examples.