
The quality of life for black people in South Africa has significantly increased since apartheid ended. For white people, it has decreased. But when you begin to lose your privilege and society starts to equalize, things will inevitably be worse when you have to actually compete with others on a fairer playing field.
You oppress people for decades, make them live in squalor and you just expect them to integrate into society immediately after generations of having less opportunity and rights? For example lock a baby in a dungeon, beat it once a week and release it into the world at 18, that child will be dysfunctional. Same principle