See: http://freakonomics.com/podcast/uber-economists-dream/ or http://www.nber.org/papers/w22627.
> So we found that in 2015, if you extrapolate to the whole U.S., we found that the overall consumer surplus added up to almost $7 billion. So people spent about $4 billion on Ubers, but they actually would have been willing to spend about $11 billion. So for every dollar people spent on Uber, they got about $1.50 worth of extra joy that they would have been willing to pay on average above and beyond what they did pay. And to put it in a context just how big this consumer surplus is, the total amount of money that went to what Uber calls the driver partners, the people who are driving the cars, was something like $2.5 billion. So the consumers got more than twice the benefit of all the money that went to the drivers. And Uber itself only got to keep about $1 billion.
Of course, none of this makes Uber immune to criticism for the way they operate as a company. And there are sufficiently many alternatives that, even without Uber, society is likely to continue reaping benefits from ride-sharing as a technology.