We got rid of all that generations ago. As a result, most blacks are now working class or higher, as are most whites. Mission accomplished.The answer is still the same and it's not going to change because it's the same answer to the question of why have the "Irish, Italians, Jewish people, Asians, etc." been able to "progress, assimilate, etc." but Black people haven't.
BECAUSE NONE OF THOSE PEOPLE ARE BLACK therefore they are not and never were subjected to the anti-Black racism that was a part of the fabric of the United States for close to 200 years of its existence.
And because there are still white and other racists who lie and claim things like "Black people need a hand up" when affirmative action only provides opportunities in an attempt to counter the impediments put in place such as the institutional racism installed by the white supremacists who created our system as well as the laws that enforce[d] the racial segregation and discrimination against Black people here in the U.S.
What affirmative action doesn't provide are shoe in jobs to unqualified Black people as you all seem intent on keeping this particular falsehood alive.