Actually I've found the opposite is true, as regards regular taxi drivers. I stopped using official yellow cabs in Southern California after my cab driver either fell-asleep or fell into a drug induced stupor while driving on the 405 south towards Irvine. I had to repeatedly hit him on the shoulder to wake him up before we smashed into the side, we were about half a second away from both being dead, I'm deadly serious. I was shaken up all evening.
I heard about Uber after that and started using them, I've only had the best experience with them. Cleaner cars, well spoken, more normal seeming drivers, a much better experience in every way, and cheaper too! In fact, for some reason, now I think about it, "real" cab drivers always seem way sketchier and suspect than all the Uber drivers I've encountered, as though Uber attracts more middle-class people and "real" taxi drivers are more likely to be lower-income and/or under-educated. I've had plenty of "real" taxi drivers seem dodgy, smelly, rude, non-English speaking. None of that with Uber.