Prediction: Uber goes the way of webvan, personal mobility is served by Google vehicles with Fedex/UPS/USPS owning the lion's share of freight self driving vehicles.
If you don't think Fedex and UPS have logistics and fleet management down to a science, I highly recommend you research their capabilities.
1. Google isn't going to be a player in personal mobility. Their technology is no more up to the task than Tesla's or anyone else's. Expect to see a few incremental improvements from all major automobile manufacturers in open-road autonomy, but nothing that's going to enable a driverless taxicab or anything like it.
2. Webvan isn't a good comparison for Uber, except in that it's dead. The actual concept behind Webvan was a good one and is now offered by many, many companies. Had it not been founded when it was, it's likely it could have raised a few more rounds, learned the lessons it needed to, and become profitable. There's nothing about Uber that's novel or interesting; from the end user's perspective, it's no different from Flywheel, which is nothing but the pre-Internet telephone-dispatched taxicab company with a new communication frontend. The only thing Uber has going for it is a structure that tries (and is now failing) to bypass regulation. Without that, it's just another taxi service.
If you don't think Fedex and UPS have logistics and fleet management down to a science, I highly recommend you research their capabilities.