That's the argument for limiting the number of taxi medallions low. And what of the drivers who now don't have that job?? Sure, you might [artificially] increase the income of the drivers that remain, but by lowering the income of the drivers that are ejected from the system. Yes, they can find themselves other jobs, but presumably if there are other jobs they could do for more money, then they already would be taking those and leaving driving behind.

Your argument is a fallacy. You ignore the harm to those drivers who end up losing their jobs.