I sincerely doubt that. I believe once driverless cars come around, there will be nothing to differentiate Uber from any other app from an established fleet management company like Avis, Hertz, or Enterprise.

Their costs would fall by that magnitude, sure. But so would everyone else's, so that doesn't immediately translate into higher margins.

I think it would benefit Uber more than rent-a-cars and other such services because of their greater effectiveness at finding rides to match with unused (driverless) cars, but that figure overstates it.

If they started to have a 50-80% unit margin, why wouldn't people compete with them? Why wouldn't, say, Amazon compete with them? It doesn't sound like a tough business to get into for Amazon -- just buy a bunch of driverless cars. And Amazon excels at competing at close to 0% margins -- why would we imagine that Uber would be successful at competing against Amazon in this scenario?