In NYC, I'll take a cab. Just about everywhere else in America I get a Lyft. Why? Because taxi dispatch sucks. The cabs never come, or they come very late. The dispatch operators are rude if you ask where the cab you called is. In some places, like Albany, NY, the cabs will take detours to pick up other passengers without asking you or telling you that's what will happen. Etc.

If you live in most of America, and want to get somewhere, and the public transit sucks, Lyft gets you there. Taxis just don't.

Cheaper. Easier ordering. You know when it will arrive. You can land in a country where people speak != your language, and still get around without having to learn the "local way". Reviews of rider and driver provide some metrics to act upon by vendor.

Speed and convenience.

People who get snarky about Uber/Facebook/etc. users don't seem to realize that these things have very real utility for millions of people. We don't just use them because we're too stupid to know better. If you want to address their (very real, glaring) problems, you'll need to offer an equally-useful alternative, not just smug moralizing.

Uber/Lyft vs Taxi

- call by tapping a few times (vs finding dispatch phone number in every city)

- reliable ETA always on screen (vs calling dispatch for unreliable estimate)

- cheaper and always shows the price before I get in (vs more expensive and no estimate)

- never taken on scenic route and usually dropped off directly at destination (vs often driver optimizes by taking scenic route or dropping off short of destination)

Is there any reason this could not happen in a taxi?

in the US, there was a problem with taxis not picking up some minorities. If you were LGBT, there was a high likelihood of harassment or abuse by the driver. These are far less likely in lyft/uber s