I used to have to try to get cabs an hour or more before going to a doctors' appointment. Cabs would just not show up and I'd have to call the dispatcher over and over. Dispatchers would tell me straight out that they wouldn't send a cab into Bayview (where I got physical therapy). To hail a cab on the street, I would have to ask strangers to do it for me while I acted like it wasn't for me (or else cabs would assume I couldn't fold my wheelchair to fit it in, or manage getting into the cab myself) So from my perspective the Uber/Lyft model has been life changing.