I have requested Ubers in almost a dozen different countries and been able to easily get a car without worrying about language barriers or being pressured into increased tourist prices. I actually deleted Uber due to the concerns about their company culture and ended up re-downloading their app because it's so helpful for international travel.
The last time I was in Berlin, Uber drivers were required to be taxi operators. The Uber app just hailed a taxi driver, so there was no real difference in getting a Uber vs hailing a cab.
Instead of each Taxi company trying to stay on top with their own individual apps (which are probably made by like 3 US companies who sell/rebrand their services to everyone), why not an app system that connects you to local Taxi services?
Support your local Taxi company. Put in your destination and get a list of rates and estimated wait times from companies .. you could put fancy Limo companies right next to the Taxis in the rare case someone wants to pay some crazy amount for a limo (or so they can use the same app to book one for a big engagement/later time).
Is there anyone in this space?
In New York, for example, hailing a hack outside of Manhattan or the trendy boros was virtually impossible. "Car service" became a thing because cabs left more than half the city unserved. But even those were limited in availability in some areas.
In Las Vegas, it was rare to see a taxi outside of the entertainment corridor. If you called for a taxi, they'd ignore you. The new state taxi commissioner even tried it, himself. He phoned three times for a taxi from a mall just a mile from The Strip, and every time he was ignored.
That's why Uber works in many places. And the app showing the position of the other cars encourages drivers to fan out into underserved areas.
Some people have even done that math and found that Ubering around town is cheaper for them than owning+maintaining+insuring+fueling a car.