"One could theorize that the descendants of chattel slavery will have (for example) less family wealth than whites who are descendants of property owners and indentured servants. "

People have even less family wealth in less stable places, plagued by war, genocide, forced expropriation, violent regime changes, state bankruptcies etc. For example, both Germany and Poland were big heaps of rubble in 1945. Nothing to inherit there but destroyed, burnt-out cities.

The 20th century in general was pretty awful outside North America. If bad history was such a universal determinant of future failure or success, the world would be one giant hopeless poverty-stricken hellhole.