> As if the problem of moving in a new nation is the strictly bureaucratic one and not the cultural one.

Could it be that you are underestimating the importance of (not dealing with) bureaucracy? It determines if you need to collect lots of documents like criminal-records certificates in each country you've lived in, to verify your degree abroad, to do a bunch of medical tests in approved institutions.

It determines what legal restrictions you need to deal with if you change jobs while your work-permit card has the name of your employer on it.

Many opportunities simply won't happen for a person separated from them with a bureaucratic boundary.