Cabs are way more expensive than Uber or Lyft and far less convenient.
There are times cabs are more convenient (not-so-busy taxi stand, hailing a cab on the street) and/or less expensive (surge pricing, flat fare routes). The majority of the time though, yeah, Uber is far better on both. Plus you don't have to fiddle around with payment, you get receipts emailed to you, you can more easily get customer support, etc. There are also many big cities (Las Vegas, Kuala Lumpur come to mind) where Uber/Grab have dramatically improved the transportation situation.
I used to never take Uber because of their role in the 1099-ization of workers, but I've accepted the fact that these services are necessary. (not necessarily Uber the company itself) It works better in some markets than others.