The premise of Uber's (in particular) valuation is that ride-sharing is a network effect market, and leaders can maintain leadership. I think as that's a scary

The premise of Uber's (in particular) valuation is that ride-sharing is a network effect market, and leaders can maintain leadership. I think as that's a scary premise to be hanging the company on. First, it's too big a market for one company to control. This isn't Facebook. Second, self driving can make this into a one-2-many market without needing Uber. Third, rides have prices. This isn't Google. A cashed up competitor can price war their way into market share. Uber won't likely be able to leverage their position in the way digital monopolies have. Prices mean price wars. If I were Uber, I would be looking for an immediate IPO.