Moreover, in some countries, regular taxi companies and taxi aggregators quickly developed similar systems. So there's no difference between Uber and them, except that local companies know their market better.
As a traveler, I want to install one app that works everywhere.
Yep, would be more convenient. Same would be cool to have single air carrier. And the same car model, that just works the same everywhere.
That would be very convenient indeed, but for whatever reason, that didn't happen. I keep running into many places where Uber is hard to find or non-existent, Turkey, parts of Mexico, Russia, I'm sure there are more.
This is why when I travel internationally I only eat McDonalds and shop at H&M.
The difference is that it's cheaper by Uber pushing down labour costs, a.k.a the driver's compensation. But since that reason isn't as pleasant, vague rationalizations are used instead.