It is important to remember that American nigger behavior is heavily rooted in redneck behavior, which originated in Ireland and Scotland. It was brought over to the new world, where black slaves picked it up from their white masters. During the boomer boom and especially after civil rights movement, nigger behavior diverged from redneck behavior to suit the unique situation the city blacks found themselves in following white flight. City crime became a big problem during the 70s and 80s and nearly all of the minority communities turned into dangerous shitholes as large numbers of blacks turned to unorganized crime and drug dealing as a means to get by. They weren't known as a criminal race before this, but there is no denying that huge numbers of them live the criminal lifestyle as a result of this. A big reason (but not the only reason) why systemic racism is still a thing is because criminal niggers still exist in large numbers.
Meanwhile, some African countries are doing just fine for themselves. Think Ethiopia, who fucked Egypt out of their water, and South Africa, who kicked the British out and made their white minorities essentially subservient.