No need to limit it to city centers. Raise prices, throttle driver recruitment, and the market will adjust accordingly. More locations will naturally lack the density of a healthy driver and passenger network.
maybe they could have uber drivers buy shiny medallions at a moderate cost, but then limit the supply of those medallions per market? drivers could sell their medallions for market value.
Sometimes, we disrupt a business, but fail to disrupt the underlying market forces that shaped the business in the first place.
I suspect that until we have robo-taxis, uber and Lyft can displace the existing taxi companies by being new and high-tech, but in the end they have the same market forces acting on their availability and pricing that act on taxi companies.
So they will wind up being the new taxi companies.
maybe they could have uber drivers buy shiny medallions at a moderate cost, but then limit the supply of those medallions per market? drivers could sell their medallions for market value.