And maybe you have lived places where this wouldn't mean anything to you, but you couldn't do this in most of the US before Uber.
Even in some well-known cities, your chances of getting a cab in < 30 min (if you could get one at all) were close to zero. There wasn't a single number to call -- you had to call many numbers and hope someone actually showed up. You couldn't track progress.
Where I grew up, my parents couldn't even get to the airport without asking a relative (and this is the biggest city in our home state).
A functioning, 24/7, predictable taxi system was absolutely not available in most of the US before Uber.