Yeah, I have worded my question poorly, but the problem here is that simply moving is sometimes so difficult that it barely remains an option.
One important reason for that is that a lot of people who have enough skills and experience to be able to find a much better job elsewhere simply are not allowed -- or face extreme obstacles -- to move to that elsewhere. Visas, work permits, relocation expenses and other issues pile up quickly.
Adding to that other factors like age, family, lack of network in the new place (which is crucial when finding a job) etc, and you will see a quite different issue than you might be used to in terms of relocation.
For starters, you'll have more money.