This probably varies a lot between cities, but the main appeal of Uber in Portland is reliability. I would love to keep it local and all, but the local cab companies (cough Radio Cab cough) would often show up hours late, if at all, even when reservations were booked a day in advance. Without a car and with public transit closed in the wee hours of the morning, cabs were my only incredibly unreliable option for getting to the airport. With Uber and Lyft I have never had issues getting to the airpot at odd hours.