Search engines are free. Whether you own or hire a self-driving car, you're going to have to pay for it, but all you really care about is whether it gets you from point A to point B. It's quite binary--either it works or it doesn't. There is objective and subjective factors the determine preferences towards search engines and phone. But if all driverless car tech works the same, then you're not going to care which one you use as long as it's the cheapest.