This assumes that your employees will just leave even if you value them fairly. In truth it's the other way around: Companies don't care for their people anymor

This assumes that your employees will just leave even if you value them fairly. In truth it's the other way around: Companies don't care for their people anymore (as seen in payment, investment in their career / training, not firing on the spot etc.) and people respond to these incentives. I also think it has nothing to do with movement between countries. The same "problem" (more like a self-inflicted wound) exists within countries if you have competitors.