Most expats do not move away altogether from their country of origin. Labor mobility ("brain drain"), even of skilled professionals, is not a negative; on the contrary, it has huge positive externalities for both the origin and the destination country, even if these don't always show up in obvious monetary terms.
People are the ultimate 'resource' for building wealth, and ensuring that people are free to move around and seek the highest and best opportunities for themselves is absolutely the best policy. (At least if a few safeguards are included to minimize, e.g. social disruption due to large-scale movement of people affecting the local culture and society in unexpected ways. 'Open borders' should never be taken literally, but it's an ideal to move towards gradually.)
People are the ultimate 'resource' for building wealth, and ensuring that people are free to move around and seek the highest and best opportunities for themselves is absolutely the best policy. (At least if a few safeguards are included to minimize, e.g. social disruption due to large-scale movement of people affecting the local culture and society in unexpected ways. 'Open borders' should never be taken literally, but it's an ideal to move towards gradually.)