We have those, they're called cabs/taxis ;) Well, I suppose they're not exactly cheap, but personally I use them so rarely that it doesn't really matter, even though I'm on a tight budget.
Imagine instead being able to use an app where, in any urban area, you can have a car sitting in front of your house in 3-5 minutes, with reasonable mileage rates, exact GPS coordinates preprogrammed, and no haggling over tip and payment method at the end of the ride.
Speaking as half a couple paying $1000 a month in car payments, car insurance, maintenance and gas, this is going to fundamentally change the calculus for private car ownership in America.
Yes. cabs are useless where I am, too. They say they will be there in 30 minutes, but that's best case.
But there are plenty of unemployed folks with cars. How much of the cab shortage is due to regulatory capture?
Imagine, for instance, an app where I could give my location, a timeframe and, say, an amount I was willing to pay. "Hey, $50 if you pick me up from the office and drive me home... if you get here within 10 minutes"
Such an app is technically easy, and I imagine there are enough people with cars either going where I'm going or simply idle to make it work. But there are... legal barriers in place.