Of course it was, but it was extremely unreliable. That's what led to the founding of Uber in the first place: https://en.wikipedia.org/wiki/Uber_%28company%29#Founding

From the Wikipedia writeup, it could very well be that they just didn't know the rules, but the experience in SF is the same: you can call a cab, but it's hit-or-miss.

To echo SilasX, there was (and in most places) no way to ensure that your taxi will acctually arrive if dispatched.

Sometimes while en route to you, they'd pick up another passenger or the wrong cab would pick you up which would frustrate many of the drivers.

Car services have always existed (with a much smaller regulatory burden than taxis), and taxis have always been significant players in the car service industry

Uber just brought it all together and brought enough players into the fold to make "car service" almost strictly superior to "taxi."

It existed in SF, but (at least at the time) the cab would only show up maybe 10% of the time.