I don't get this. Supplying a ride sharing app, especially just supporting one, should have very minimal overhead. If Uber didn't have other interests like self driving research, they could be distilled down to a small startup's worth of support devs and one manager and just let the app make money. A revenue of 3 billion would be way more than sustainable being split among a company size of 10 or even 30. If anything, if forced by circumstances they could just cut all the fat and massively, massively downsize while staying the same from the consumer's perspective. VC's know this so growing for now and investing in R&D is fine when at a moment's notice a company could be reduced to 30 people and just keep supporting an app.