it varies by person, but for me, uber is stealing jobs from car salesmen, because I have delayed buying a car because I don't really need one because it's cheaper for me to take uber when I really need it, combined with shopping local and transit.
The ultimate truth is that we as a society are wasting a lot of money by buying expensive machines and then parking them in a lot, or hiring expensive drivers but then they are only actually on the clock a small portion of time. think about it - you spent $30k for the car in your garage - what percent of the day is it actually used? 10%? less? wouldn't it make sense that instead of parking money in a spot it is used to provide service, so that one car can serve 5 people instead of there be 5 cars that are hardly used? this is the opportunity that uber provides.
Same with taxi drivers. yes, rates are much lower, but you can get more fares and spend a greater % of your day with a passenger.
the biggest opportunity for uber is to make cars be used a greater portion of the day. this is the benefit for everybody.