In Vietnam, if you see a parked driver waiting for a call, you can show him your Grab (ie, Asian copy of Uber) price to go somewhere, then get the same ride for 80%.
A similar thing happened to me in South America while on vacation, I was looking to book an Uber but the taxi driver gave me a small discount to do it "on the side" and explained that he wouldn't see most of the money from Uber.
As a passenger, the advantage of Uber is that if something happens, I have someone accountable: drive + car plate. But in reality I don't know if that works
