Before Roger Bannister broke the "four minute barrier" in 1954, people didn't believe it was possible to go faster than a 4 minute mile. Once Roger Bannister showed it could be done, his record was promptly toppled and having a less than four minute mile is no longer as big a deal.
Wakanda is a fictional African society in which Black people thrive in their own isolated, technologically advanced bubble. The implication is, left to their own devices, Africans can excel.
Many Black people have not been exposed to legitimately wealthy and successful people who look like them. The idea of a society like Wakanda defies imagination. Enter the Black Panther movie - seeing is believing which leads eventually to achieving.