You can't have global pay harmonisation in floating rate currencies. Harmonisation is fixed exchange rate thinking. It would happen between Scotland and London

You can't have global pay harmonisation in floating rate currencies. Harmonisation is fixed exchange rate thinking. It would happen between Scotland and London, but not (to the same extent) between Poland and London. Once you move something abroad the output becomes an import which ultimately has to be balanced by an export (or mercantilist tricks which is a whole other discussion - see China for details). The correct response would be to unionise, rather than throw hands up in the air and continue to feel exploited. There is a shortage of skilled staff. If your current employer doesn't appreciate you, then find one that does.