Multiculturalists love the legacy of slavery causal explanation for African-American problems.
Because it cannot be undone. It implies that whites are permanently guilty and permanently liable, no matter the consequences. To them, it doesn't matter whether Whites have already given umpteen trillion in welfare, health care, affirmative action, and other benefits to African-Americans.
The word cause means to change the probability of a thing occurring. Bringing African slaves to the Western Hemisphere was a cause of what happens to African-Americans, just as millions of other causes were and are. Otherwise, there would be few, if any, African-Americans and few African-American events.
But the problem with overemphasizing these distant historical causes and harms are that a) the villains are dead, b) millions of distant historical causes exist, c) they lead to mutually destructive tit-for-tat conflicts, d) they de-emphasize policies that would make things better, e) they help ruling groups exploit us with divide-and-screw policies.
The English treated the Irish worse than they treated African-Americans. Would Ireland be a better place today if today's Irish spent massive energies denouncing the British and demanding reparations? I doubt it.
If Africans and African-Americans started pursuing a rigorous program of eugenics 100 years ago, life would be much better for them than chanting the legacy of slavery. But that didn't happen.
Robert Mugabe and his successors will still blame whites as they loot what little wealth Zimbabwe creates in the future.
Multitudes of events (bad luck, good luck, volcanic eruptions, comet collisions, manorial feudalism, random mutations, harmful policies, beneficial policies, the evolution of malaria, Middle Eastern religious texts, etc.) caused our present situations. We can't change that they happened. It would do whites no good to endlessly blame manorial feudalism for our present decline. Sure, we should note what manorial feudalism caused but not dwell on it.
Every racial group has suffered grievous harms from ethnoracial outgroups in prior centuries. Bantu tribes enslaved and wiped out multitudes of outgroups, including Bushmen and other hominids.
Despite establishment propaganda to the contrary, Southwest Asians and North Africans have caused massive harms to Europeans and black Africans for centuries, including slave taking that dwarfed the trans-Atlantic slave trade. But they seldom mention that legacy of slavery, a far more brutal death camp form of slavery. Or the slavery White establishments inflicted upon other Whites. Nevertheless, Whites shouldn't sit around demanding reparations from Arabs and other Southwest Asians.
We must focus on liberating our own lives and nations from every ingroup and outgroup that seeks to harm and destroy us.