What do you think most people use when they need a taxi now days? Humans believe the market is some kind of magical place where everyone gets a slice of the pie. This is not true, winners are a thing.
The taxi market is still pretty fragmented. Markets evolve in different ways depending on the nature of the goods and services being exchanged and the environment in which they operate.
Which is one reason why robust antitrust enforcement is necessary, yet most of the antitrust laws on the books have barely been enforced since the late 70s.