If it's not Uber, someone else offering a similar service will eventually allow people to submit their own self-driving car to a driving pool when they're not p

If it's not Uber, someone else offering a similar service will eventually allow people to submit their own self-driving car to a driving pool when they're not personally using it. Or people will buy a car and submit it to Uber's pool for some return, as an investment. Minimises Uber's costs which will mean they can expand aggressively.