The rich don't live off the backs of the poor so much as the rich are rich because they hog the resources. Most of the imports from Africa are capital intensiv

The rich don't live off the backs of the poor so much as the rich are rich because they hog the resources. Most of the imports from Africa are capital intensive raw resources, they aren't products with significant labour value add. If the population shrunk the remaining one billion would be much richer unless you also took away the society's built resources at the same time.