I don't think they have hit true market dynamics yet (rides are subsidized), so comfortable might be a strong word here.
There have been a number of "Uber is cheaper than taxis because they are losing money" newspaper articles, but they usually point to the loss of the company as a whole.
A duopoly the likes of which not seen since that of Yellow and Checker.
It's just as easy to rent a self-driving Camry from Toyota.
Oh and then there's the thing where Google and Apple and probably a hundred startup hopefuls scraping APIs will try to disintermediate them at the device.
Think credit cards, collaboration with last-mile transportation (Uber + Bird), discounts on restaurants, things of that nature. They can and are working towards building more of a brand ecosystem.
Who is going to pay for these discounts? Uber's investors?
Given the money the entire industry has spent on self driving cars and gotten little reward for, I don't think anyone is getting replaced for a very long time.
The two scenarios I can see are
1). That their ride-matching platform will still play a role in a self-driving world. However, I think a worst case for Uber is Waymo gets there first and then Google can almost trivially replace Uber with their own matching platform.
2.) They acquire a startup that has a successful direct self-driving play.
Either way, the economics of their core offering changes drastically. I have a hard time believing investors in Uber aren’t pricing this in at least somewhat accurately.
I don't see how this business model even works.