Botswana, Namibia, Rwanda, Kenya, Ghana and Zambia are faring pretty well, all things considered. There are numerous countries that show it is possible to have a functional and stable black-majority state. It's just that the U.S. ended up with a dysgenically-selected population that on average, is quite shitty on a contemporary cultural level. I think Americans (and to a certain extent Europeans) tend to view their domestic black population as a monolithic stand-in for the global black population. Yeah, there are many dysfunctional black majority areas, but competent ones can and do exist. Botswana ranks better than several European countries when it comes to stability and corruption, for example.