Is there any evidence that Uber is even on par with the self-driving technology of Google, Cruise, or Tesla?
https://newsroom.uber.com/san-francisco-your-self-driving-ub...
https://www.theguardian.com/technology/2016/dec/16/uber-self...
Because deploying Robotaxi fleets will be so capital intensive, no single company is likely to dominate the way Uber has in rideshare. There is enough demand spread out across enough different cities that they won't need to compete directly for a long time.
If they can't maintain their market share in a driverless car world, it's difficult to imagine how they can justify their current valuation.