This article claims Uber will never be profitable for a number of reasons, including competition with other platforms:
https://news.google.com/articles/CAI...S&ceid=US%3Aen
I think driver/car-sharing could be the thing that helps Uber achieve both brand-loyalty and cost-savings that put it in the lead.
Basically, Uber needs to become a car-share network whose app allows car-sharers to ride and/or give rides as part of the car-sharing package.
Recently, I read that Uber is getting more selective about who gets to ride as a passenger, and that is a good start for preventing abuses that can cut into its profitability.
As long as both drivers' and passengers' identities are known and verified, that should prevent moles from posing as passengers and/or drivers to generate negative publicity for Uber.
As a seamless network of rides/drives in shared vehicles, Uber will basically be able to drive the costs of (shared) car ownership down to extremely competitive levels.
For other ride-share apps to compete, they would have to find a way to facilitate driver/vehicle sharing, which would be quite difficult according to what posters have said in this thread.