In recent years, most of the people want to move abroad for better opportunities. Although, that can bring some challenges such as economical decrease for countries that people leave, it allows people be more prodoctive with better standarts and I believe this advantage far outweighs any potential disadvantages.
One downside of migrations might be facing economical problems in not developed or developing countries. Generally, individuals who prefer to move developed country be educational and with potential and they do so for better education and job opportunities which their country does not have. As a result, countires where people leave, loose their educational workforce and in long term, it affect as decline their economical growth. However, I think this can be avoided if countries attracting potential people from economically weaker countries.
On the positive side, living and studing in developed countries offers people be more productive in global way. Individuals who study in better conditions can reach their full potential and can be more profitable for not only country they live but also country they leave. more excellent skills people can make huge changes and bring global develepmont to highest level in so many different field. I think that opportunities like these are extremely important because if they do not migrate for better options, they might not be fully productive.
In conclusion, although leaving poor countries for high level life standarts can be cause stagnation and regression for those countries I believe this downside is greatly outweighed by the upside that when individuals reached their full potentials and abilities, this results in much more global contributions.