I dated a girl that has Caribbean ancestry and her parents would punish her for even jokingly using ebonics and shit. The racist "blacks are genetically inferior niggers" doesn't really stand up when you look at immigrant Africans and blacks and and also even when you look at racial stereotypes from past cultures. Africans being unintelligent didn't register with ancient cultures that interacted with them on occasion (such as the Romans). In fact that ancient world had much different sets of stereotypes towards groups we'd vaguely consider to be races today to some extent.
The problem is American liberals tell blacks that they're held down and they can't get anywhere unless they vote for liberals--just look at Biden's recent gaffe saying that if you're voting for Trump over him, you're not black--and the lefts increasing radicalism and sometimes-hidden, sometimes-not-so-hidden flirtation with socialism and far-left ideologies mean they NEED things to be bad and need to emphasis solely the bad in order to attribute it to American capitalism and culture. The left quite simply needs black people to feel disenfranchised and targeted. Despite how much better things are today than they were in the 70s and 80s the feelings are getting worse because the left can't survive if they say things are actually getting better and not worse.
Can you imagine how much harder the left would have it if they didn't have racial conflict to fall on? If racial tensions ever get solved suddenly a bunch of democrat politicians are out of jobs and leftwing radicals would have to attribute social progress to something other than the workers owning the means of production, and they'll never have that.
That's not to say the right wing isn't causing damage on this front as well. Their inability to do anything about the thuglike police forces and question this level of authority, and their haughtiness towards things like marijuana are just making the country worse. They'll defend gun ownership and say that even if you ban guns, you'll never get rid of people having them and then turn around and argue for ruining people's lives for a plant that make you feel funny--as if making pot illegal is going to stop people from wanting to get high as an escape from their problems. Given that marijuana is still a cultural thing with African Americans these stupid laws hurt them as a group the most.