It's just a cab company. Depending where you live it might be better than the existing cab companies.
It's cheaper than some cab companies, but that's because it doesn't always comply with local regulation and because it's burning money from capital investors.
Uber doesn't make much sense in the UK, where you have the choice of taxis (can pick up from the side of the road, must use taximeters for pricing) and cabs (can't pick up from side of road, can pre-arrange a price).
I just can't imagine that random people who play what is essentially a glorified computer game would be reliable enough to show up at 4AM and get me to the airport safely.
Or provide a reliable service in any other emergency or inconvenient situation - you don't use a taxi to go to the grocery store or to commute to work, you use it in emergencies.
I can see how an app to call a taxi and track rides is a good thing, but i can't see how having random people provide the actual rides is a good idea.
I am certainly surprised to not hear more about this and there has never been any study. It should be fairly easy to compare the income with the costs of running a car.
That being said, regular taxis used to be ripped off by the medallion and the car rental, so they might not do better.
I think GP is trying to understand why it has so much media exposure.
It has so much media exposure because on the one hand, it spends a lot of money on aggressively marketing itself (thus people talk about them), and on the other hand, in many places their business is entirely based on breaking local laws (thus people talk about them). Plus, they're beloved Silicon Valley unicorn (more talking) known for pulling off shady shit left and right (even more talking).
But beyond that, they're just a taxi company with a nice app and shitty attitude.
Is it just a passing fad of some sort, like fidget spinners?