Don't forget conveniece.
Many people are very happy to pay pretty much any premium just to be able to travel from wherever they want (rather than from a fixed point nowhere near where I want to travel from), to wherever they want to, door-to-door (rather than to somewhere with no door, not remotely near where I want to arrive). Oh, and can I travel whenever it's convenient for me?
Taxis are OK but they don't score too highly on the other major factor - comfort.
Which is more appealing? - (a) a nicely upholstered seat in an environment with climate control and a choice of entertainment options, all delivered with 14 speaker surround sound or (b) a 1 in 5 chance of a seat on which god knows what has already been dribbled, spilled and excreted, probably within nasal assault range of somone who clearly uses their underwear instead of Andrex?
No contest!