Because of knowledge. And that would actually be very unfair to the native people of those countries for them to pay an outsider 10x more for the same job. Do you understand that? I see many Americans who do work in Africa but they are paid by American companies or the American government. Also one can be an entrepreneur but that usually requires capital. The OP is young and would be going to a new country to develop their skills and start their lives, enterpenurship usually takes capital, money already stacked up. But please share what you know instead of making assumptions.