The countries in Africa that seem to be doing the best are those that are mostly homogenous. Those that have many differing groups in a country whose borders were drawn up by agreements between European powers for their own benefit have lots of problems including violent conflict. Ideally the countries of Africa would get together and redraw their borders to be more aligned with the various differing population groups but unfortunately that is unlikely to ever happen as some valuable natural resources would change which group gets to benefit from them. The closest this has come to happening was the split of South Sudan from Sudan, but the oil curse has kept that from being a harmonious divorce.