In Singapore grab has added taxi's to it's fixed price or you can book a taxi with normal meter fare. At peak periods taxi with meter is about 25-35% cheaper and without peak 5-10% cheaper. The government has also allowed taxi companies to offer fixed fares from their apps the way things are going I don't think uber will be able to compete very long if it actually tries to be profitable.
So until taxicab operators in major cities get a nifty app with guaranteed pricing most of people would just limit the price comparison to Uber vs Lyft.