I donno. I keep thinking about this all the time. I might also be blinded by the intricacies of where I live, Bangalore. Cancellations by Uber drivers are rampant here and it's very hard to find the black equivalent. The UberXL service which counts as the black equivalent has absolutely zero predictability. My guess is that there are at least 10,000 - 20,000 people in Bangalore, a city of 10M willing to pay a 2 - 3x premium for predictability and good QoS. There simply is no such option for non airport rides.