If you take a truly long-term view, the marketplace for on-demand drivers will become obsolete once autonomous driving becomes good enough to be adopted everywhere. At that point, Uber's biggest edge -financing and supply-side field logistics- will erode very quickly against companies that own vehicle production (auto giants) and AI (autonomous driving)
Uber knows this, and that's why they have been investing a lot of money on robotics and AI around their partnership with CMU. However, they still do not get the kind of data Google can get from their Maps and Waze (It's interesting to note that Lyft and Waze partnered) to enable their AI researchers.
Uber is still going to be a very successful company in the next few years: For technical and legal reasons, self-driving, on-demand vehicle services will be at least a decade out. But I'm not as sure about Uber's survival in, say, 20 years.