Blacks were promised something from 1954-1965 that they have not received. The people who did the promising never considered the possibility that what they had promised could never be delivered.
The material circumstances in their communities, in their families, etc. deteriorate relentlessly.
This is why there is a panic-driven search for “racists”, as if the least-racist generation of whites ever in the history of the world are somehow manipulating events to harm black people.
It’s odd that, when public and legal racism was permitted and even applauded, the material conditions in black communities were much better than they are now.
I think the leftists get us all to think/talk too much of “black communities” as monolithic — in fact there is a vast range in behaviors, economic circumstances, etc. For millions of black Americans life is exceptionally good and comfortable in a middle class to upper middle class lifestyle, certainly with far better material circumstances than ANY of my “white” forbears ever enjoyed before the 1970s-80s.
The millions of black Americans who are not doing well are largely caught up in cycles of their own (or parental) bad behaviors: illegitimacy and broken families, poor life choices, too much crime, etc.
Not that it’s always a simple either/or for any family, race, or community.... but there are many millions of American blacks who are doing quite quite well no matter what the “Racism Propagandists” try to say about it.
The big problems are for all the people in America (of any race/background) who are not committed to working hard and honestly for the true American Dreams.
There’s some truth to what you say, of promises unkept. Of course, these were illegitimate promises, but that falls on deaf ears.