May the most efficient vertically integrated conglomerate win then.

So to play devil's advocate if that's how you believe things will play out... what happens to the existing car companies once new car sales start dropping precipitously? There are more car manufacturers that will be fighting over the same shrinking pie of new car sales than there are global TNCs. Their valuations will likely drop to the point where they could become an acquisition target for Uber. The only competitive advantage Tesla has is in batteries, and that will likely become a commodity insofar as TNCs are concerned far before it's a competitive advantage. The daily driving distances a battery needs to support for TNC use is a lot lower than an individual looking to do long road trips.

Uber won't last long enough to acquire a traditional automaker before technology creates a death spiral for those automakers. I'm wrong if they can find additional investors willing to gamble on the expected duration of time till that happens (~5 years at least).

Tesla has a product people will buy today (with ~25% margins!), as well as a team to transition to ridesharing in the future. They're collecting millions of miles per day of autopilot data and that'll only increase with the model 3 rollout.