This always needs repeating.
According to United Nations statistics of the time, during the 1960s, 1970s, blacks in white-ruled Rhodesia and apartheid South Africa had the highest wages, the highest standard of living, the highest quality of health and medical care, of all blacks in Africa south of the Sahara.
This is NOT to defend minority rule or apartheid; it is ONLY to point out the abysmal quality of life that exists in Africa south of the Sahara, in all these black-run black countries.
This is much like the question of, had the white slave owners left their plantations to the slaves to run after denying them education and experience in the day to day upkeep of the land, what would have happend to southern states.
When a parent takes their children and does everything for them, refuses to allow them to make their own decisions or insist on them becoming educated, then moves away leaving the children at home to fend for themselves, it is not the fault of the kids that the roof leaks or the house falls apart.
Society has a habit of marching into lands that are not as advanced as they are. The new people have no interest in the betterment of the society they take over, they are only interested in how they can gain the riches of the land and people.
What do the New people care about anything but themselves, so when the mines run out of ore, everything of value has been looted from that country they leave these people in the hands of the bully's and ignorant people that have no idea how to put their land back together again.
It may have taken 3,000 years to developer this land yet it is expected that after complete devastation it to be rebuilt to its original state in 25-50 years.
What a wonderful argument this makes for the last leaders as to why their actions were valid.
" We gave them everything, under our rule the people were fed and clothed, as long as we were there to dictate their daily lives they had it easy. We did have problems with some of the misguided population that objected to our rule but we managed to shut them down. For 150 years we have led them into prosperity and when the population banded together to throw us out and allow them to make their own decisions, we left them only to watch as they dissolved into chaos. Not our fault these people cannot rule themselves, not our fault the people do not line up in droves to be educated and somehow learn economics, science and technology."