Lack of generational education.
Lack of generational wealth.
Lingering distrust of the majority.
Angry portions of the majority race.
Assumptions about one race by people in power. (police)
Being one generation away from many employers refusing jobs.
One very specific example... When I was in College, 1990's, black students were not allowed in white fraternities. Fraternities are more than just party houses, they are also a mutual cooperation association. If a frat brother can help you get a job, he will.
Another example... When I was a kid in the 80's black people were not allowed to be members of the most prominent social clubs in Tampa. The Palma Ceia Golf and Country Club did not allow black members. This was not just a club for people who liked Golf, these people did business together, often exclusively, if you wanted to do anything big or that required money in Tampa, you needed to belong. My father hated the Club, but he had an architecture firm and 6 kids to feed, if he wanted the big jobs in Tampa he had to be a member.
Yes, things are changing, but black people MY AGE grew up when their parents were not allowed equal access to the wealth of their communities. Yes, there were exceptions, but the community standards were that they were not allowed.
This affects kids, and their kids and it lessens generation by generation, but its not gone yet.
https://www.pcgc.org/ This is where I grew up, and where I made my lifelong friends. Its where I get much of my business today.