As I see it, the only acceptable outcome for Uber at this point is gaining a huge lead in the establishment of an autonomous driving fleet.

I don't see any way its current businesses (e.g. app-based taxi service, food delivery, etc.) justify its valuation. The question then is whether reliable fully-autonomous cars are 2 years out, 10 years out, or more; even the experts can't agree. Uber needs it more than Google needs it, more than Tesla, more than anybody.