Segregation did not necessarily preclude success. That depended on where you were and the culture around you.
As a child I knew successful black businessmen and tradesmen in our rural community who were well known and respected members of the community, respected by both blacks and whites. But those were days when black children went to school, taught by black teachers and Principals who would discipline those children. When we were integrated into the "black" school (1960s), it was the white kids who caught hell for being unruly, the black kids were well behaved--and THE ticket to prosperity was seen as an education, both by parents and students alike. Those I knew who saw no other way forward beyond high school were contemplating joining the Service so they could go to college on the GI Bill when they got out--white and black, alike. Others were learning trades, but the focus was on a home with a wife and husband and the (statistically) ordinary 2.4 kids. (If you framed tobacco, you might double or triple that number--it's labor intensive)
So, what happened to shut that down? Race riots didn't help, incited by paid agitators from Washington, D.C. (the High School was 25 miles south of there). One of the students was hauled off by the FBI for activities having to do with the destruction in Cambridge, MD, running with H. Rap Brown, Stokeley Carmichael, and Eldridge Cleaver. The resulting riots derailed much of those ambitions, as acquiring an education in that school was virtually impossible during the years of unrest. That affected whites and blacks (50/50 student body), and only those who could afford an out (after school or private classes, or private school) or who lived across the line in another gerrymandered school district did well. Lifelong black friends, rather than end up with us both in the no man's land of that conflict, simply said "I can't know you, not here, and you can't know me". White teachers and administrators did not DARE to discipline black students, and with a lack of disciplinary influence, the place became like something out of Lord of the Flies, at least until the MD State Police started walking the halls with K-9 dogs, with all but two entrances to a 1200 student school chained and locked shut.
(Thankfully, I got to finish my High School education at a private school, at a cost only about 5% of what it costs to go there now).
In the meantime, LBJ's great society was busy setting up to subsidize failure, and a little known fact was that in order for a woman to be eligible for welfare to feed the kids, daddy could not live at home. That did more to lay the groundwork for the current malaise that afflicts a significant (now multi-cultural, multigenerational) demographic than anything I can think of: It broke the nuclear family, and with it, eventually broke the idea of a home with Mother, Father, and children in some circles. Given the choice of being homeless, unemployed, and facing high rents, what's an urban mother to do? Rural whites still (although not as much as then) refuse to go on 'relief', although that barrier has broken down over time, as has the cultural resistance to having children out of wedlock. That is a statistic that has risen across the board, despite readily available contraceptives.
(The slumlords are the ones who really made out on that deal--"subsidized housing"). Rural life was more forgiving in that almost everyone could find work they needed done to help out and preserve dignity at the same time.
But we have been paying to promote failure, and like I said, it isn't confined to blacks.
I'm not judging anyone on the basis of appearance. I know some people do that, I have seen it. My wife, and family on her side are Chippewa (not 'res', but tribal members), and I have seen subtle (commonly bureaucratic nonsense) allusions to the ability of native children to learn. I have found them very capable, but a school system that can barely teach whites and has a 24% drop out rate kicks them to the curb (along with anyone else, I don't believe it is just a racial thing) the second they have problems with a subject, and that has become even worse while teachers hide behind COVID.
I have seen students who embrace conservative concepts get scuttled by the liberals in the school systems and it makes my blood boil. Long ago, in Puddin'head Wilson Mark Twain took on the argument between nature and nurture being the determinant. The argument existed before that. We still haven't resolved it.
The Darwinian mindset blamed nature, and promptly used that theory to subjugate and exploit whomever it could, claiming the genetic high ground on the basis of technology it borrowed from the orientals (gunpowder) and developed further.
Others have postulated nurture, blaming this clan or that, or their belief system (protestant v Catholic), there is always some exploitable divide by which those in power can manipulate those who are not, and keep it that way.
In reality, we will never know. If a genetic marker for intelligence (raw intellectual capability) was found, than the outcry of "racism" would drown out any science involved. But without the cultural affirmation or some abnormal innate desire simply to learn, or other incentives, even those with potential genius would not be successful.
Culture (nurture) and quite possibly nature (raw, genetic ability) go hand in hand to develop any person, regardless of color.
So how about we just quit playing games and allow each to rise on their own merits?
If anything I have said makes you believe I'm a racist, well, you're wrong. I live where I live, partly because when I got here, you were seen as standing as tall as your deeds, as reliable as your word. Those are things I live by, and I don't need to put anyone else down when I can stand tall enough on my own.