most people are just not ready to move away from their home/family. and even most of those that are would only move to a country where they speak the same language. that means germany or switzerland. and there it means places where they can find a job, which tends to be the larger more expensive cities.
so despite the cost of living, it is really hard to find other cities that offer the same quality of life at less cost.
in short, moving within europe, while possible is not as easy as moving within the US. and moving outside the EU is even more difficult, so very few do it.
also, vienna has massive growth in the last decade, but i think most of those people come from places that are even worse.
