When I was in London a few weeks ago the taxi prices were 2-3x the uber prices. Also they'd tell you to fuck off if they didn't want to take you to that location.
I’d rather give a call than install an app anyways.
My experience taught me that taxis are usually around the same price as Ubers in densely populated areas and wildly more expensive outside of those. I’m not very experienced as an Uber user though since I generally prefer public transport.
(I kid, I live in Peckham).