I don't know much about Uber, I don't see how their model is different from a regular taxi. They both need to pick you up at your current location and then you need to tell them where to go.
I don't see how Uber knowing in advance where you want to go could change the outcome.
No, in fact it's the taxi drivers that usually have more information about rides than Uber drivers.
Once booked, an Uber car can not be flagged someone else, it can not hear about other people needing rides to other locations, and it can not make itself available for other tentative bookings. First in, first out. That's how it works. There is no inventory sitting in queues waiting midway to be processed (if you don't mind me using the metaphors of lean manufacturing).
In the case of a taxi however, even if they're using a taxi app, there is no guarantee that they're coming to pick you up, because someone else could flag them on the way, they may get a more attractive offer of someone needing a ride to the airport (instead of a five minutes ride), they may not like the color of your skin or the way you're dressed or the way you speak, and they're always trying to book their next ride before they're finished with their existing one.
In the case of Uber also, the inability to do double-booking is important, but it's not the only thing that makes the service better. Since the transaction goes through whether you're picked up or not, you better be there when the Uber driver shows up. And the Uber driver better pick you up, because otherwise he'll get a charge back on his account and he'll get a very bad customer rating on his profile (assuming the gps data from both phones do not contradict the story of the customer).
Not only that, but as a user using the Uber app, you're instantly reassured after ordering the Uber car, since you're seeing its dot immediately moving towards you. In the case of a taxi however, even if you were to pinpoint its real-time location on a map, you would probably see the dot moving away from you as it is trying to finish its last ride.
Combine that with the fact that the medaillon system is archaic and highly inflexible, it's no wonder medaillon holders are not happy. During peak hours, Uber drivers can come out of nowhere. Their marginal costs for Uber are constant. In the case of a medaillon holder however, during peak hours, he can't split his medaillon(s) in two. The most he can do is to force a rotation of drivers to use his medaillon 24 hours a day 7 days a week even during low peak hours, to make sure he squeezes out every penny that he can out of that medaillon (or medaillons) so he can try to recoup his investment. And that doesn't solve the problem, that in places like New York or San Francisco, there are not enough taxis during peak hours, so it's not even worth trying to get one during those times. So before services like Uber came along, people opted for public transportation if they could during peak hours, or they opted to bring in their own car, and paid outrageous amounts for parking.