> pay for insurance, gas, tires, oil changes, parking, washing etc.

If you use a car you are paying for those costs. There is no getting around it. If you uber it is indirect, but part of your costs per ride is going to those things. Renting a car gets someone else to do them - but you are paying them to do that somehow. (self driving make trade parking for gas where parking is expensive, so in the densits areas this can make sense, but only because the car is driving empty out to the suburbs in the morning and empty back into the city in the evening - so it increases traffic)

If you own your car you can choose to not keep it clean. The rental will not allow that choice and so you pay for it.