Sure it's easy to take a cab. What's more tricky, is not getting scammed. E.g. in Vietnam you'll be looking about various internet sources on which taxi companies are probably not gonna scam you. In France, I had some friends getting scammed in a separate ride from mine.

In general, the ability to know beforehand the price, is golden!

Adding to this: in countries payment can also be a problem, trivially solved via Uber. Take e.g. when I first arrived in South Korea and took an cab from the airport (fixed rates and in cabs in Korea are nice, so not a complaint there), the taxi couldn't take my card, and I didn't have 100k won in cash (accidentally took a luxury cab), so we had to drive around to find a bank that luckily took VISA.

I am not sure how you were able to communicate if you could not write or speak directions, but I am impressed! I don't think it wasn't possible to do before Uber in general, just for my case.

Map, and a finger. Or a piece of paper with a hotel name written on it. Are people really becoming so incapable of navigating life without a phone?

Depends on the country. Travel to a difficult country, or a rural area of pretty much any country, and get back to us.

What do you consider a "difficult" country? I used to lug a kayak around South America with me on public transport and taxis or even the back of trucks that were going the right way (while speaking the language very poorly). The biggest problem I had was getting a taxi in Hungary where the letters look the same but the pronunciation is quite different. Even then it was a case of getting a map out and pointing to the street.