I drove for Uber for almost a year when I was between jobs. The hours I chose were generally 3am-noon (early because I like mornings, but late enough to dodge most of the drunks). The majority of my passengers were people going to and from factory jobs.
A large number of those passengers were people who didn't speak English whose English-speaking children would order the Uber for them. I didn't notice it at first, but after a few pick-up confusions where the passenger handed me a phone to talk to the person who actually ordered the ride, one of them explained it to me.
I live in a transit-sparse city, and a surprising number of poor people use Uber as their main means of getting around. It's simply cheaper than owning a car, especially if you don't have money up front, a steady job, or exceptional credit (Notice how car ads on TV are now disclaiming their advertised interest rates to indicate those rates are only for people with the best credit).
Even for me, now being an office-dwelling developer, if I factor in the cost of just a car payment and fuel, Ubering to work would be cheaper than owning a car. And that's before factoring in insurance, repairs, maintenance, etc... If I didn't enjoy weekend road trips, I'd ditch the car altogether.
For example this map is the night bus map just for the area around the Bank of England, and most of those will run at 15 minute intervals: http://content.tfl.gov.uk/bus-route-maps/city-of-london-nigh...
This is not unusual - other maps exist for other parts of London, and even when I lived in W6 (Zone 2), I could get a bus at all hours of the night from Piccadilly Circus to my home or vice versa. Even now living out in TW1 which is some 11 miles out from central London, I can get a night bus all night, every night to and from Oxford Circus.
Costs are also low: £1.50 a ride, with a second ride taken within 60 minutes of your first ride being free/included.
Realisitically that means you can easily get from one side of London to the other in the middle of the night for £1.50 - £3.00. It might not be the most direct or fastest route, but it's popular, and with good and obvious reason.
Tubes also run all night on some routes a few nights a week, and even when they don't 5am is a typical start time.
Poor people don't tend to use Uber in London as a utility that it sounds like happened in your city - it's a luxury product with luxury prices. Their target market here are those who are drinking and meeting friends off the beaten path from home or work on the tube network.
However, I was replying to someone who could not grasp that anywhere "on the planet" would poor people use Uber.
Most public transit services have reduced service on nights and weekends; so, in a world where you don't have a car; you can take the train/bus to get to a shift in the day, but must take a cab or uber home.
It seems obvious that Ubers or Taxis would serve this purpose wherever vehicle ownership is cost prohibitive and public transit is at all available.
Likely, this isn't "the poor" but inclusive of much of the working class in modern cities.
The working class does not in general commute by Uber in London.
On what planet are "the poor" commuting back and forth to work via Uber?