That's a little different from your original question. To answer it directly, there are still some vestiges of institutional racism and other barriers that disproportionately affect black people. Obviously things are better than they used to be, but I wouldn't say it's perfect or that it's an even playing field.
More broadly, I think it's just basic causality- that the past affects the present- and that things take time to change. I know that sounds obvious, but it's so often overlooked.
The black middle class has never been as wealthy as the white middle class. There are crazy stats out there; something like the average white family has 20x the net worth of the average black family. And the greatest source of wealth for the middle class, black or white or otherwise, is and historically has been home equity. Both of my grandfathers served in WWII, and after the war they were able to buy houses and pursue advanced degrees thanks to the GI Bill and VA loans. These were opportunities that were systematically denied to many black WWII veterans who received less-than-honorable discharges due to rampant institutional racism. My dad served in Vietnam and did the same thing. Though housing prices and interest rates were a lot higher for him in the mid 1970's than they were in the 40's/50's for my grandfathers, he was still able to own a home and get his master's degree and get a sweet job, which he used to support my mom while she got a law degree and then made even more money. This was during the same time when banks were redlining and homeowners' covenants were blocking black people from buying into "nice" neighborhoods. White Citizens' Councils were still a thing and barely a decade had passed since the '64 CRA and the '65 VRA. When my grandparents died, they passed down properties they had paid off through the course of their careers. When my parents die, they will pass down this wealth to me and my siblings. And so on.
All of that accumulated wealth makes a huge difference. And all of it is a function of the past and the way things used to be.
Considering everything else, I just don't see how one could honestly arrive at the conclusion that social welfare is to blame.