Nobody is saying the city will cease to function because no ordinary workers can be found. But there are problems. Perhaps the simplest of which: I personally

Nobody is saying the city will cease to function because no ordinary workers can be found. But there are problems. Perhaps the simplest of which: I personally feel like you ought to be able to live in the city you serve. The more complex problems get into the inter-city dynamics, the sleepy commuter towns, the slums that wind up surrounding the wealthy areas...