Incompatibility is an even harder problem than you say-- there's a town of 20,000 people. Times get hard, and half of them want to leave, but that will seriously disrupt the social fabric. To what extent is it possible for people to get what they want?

Okay, add a social safety net so that no one is driven away by poverty. However, different places appeal more to people of different ages. That stable small town is a good place for raising small children, but too boring for a lot of teenagers, many of whose parents don't want them to move to the big city.

The interesting question might be "How close can we get to a society where people can live under the circumstances they prefer?", and the answer is probably "Not all that close, but closer than what we've got now."