There have been plenty of smart black people, Thomas Sowell, Clarence Thomas, Candace Owens, Kimberly Klacik etc.
If outliers can exist then the problem isn't because they're black, it's the welfare state, the poor education, drugs and the culture that developed around all of that. It's the ones that escape all of that that end up doing well.
Trust me, they're probably using a very loose definition of Qanon