Pinker's book Better Angels of Our Nature documents, among other things, how ethnic conflicts have been successfully dismantled around the world. A key part of the successful recipe is a final round of partial justice whereupon only the most egregious crimes get addressed, the aggressors accept the truth of what they did, issue full apologies, and all claims are extinguished. There is no attempt at real justice, but it does end conflict and leaves everyone better off.
By contrast cries for justice have historically resulted in a new round of conflict, which creates a round of retribution, and a continuation of conflict that leaves everyone worse off.
The USA went through this effort after the Civil War. All claims to reparations for slavery should be considered long extinguished. And as much as you don't like it, the US descendants of slavery are massively better off than their ancestors were, and are likewise both better off and happier than most of their relatives in Africa.
It is clear that injustice is not done. I fully support an end to the Drug War, a reduction of prison sentences and a similar round to end the ongoing and current conflict over the same. Not based on long past claims to victimhood based on the slave trade, but based on current injustice.
However we have a lot more examples today of how to successfully end ethnic problems in countries as diverse as Northern Ireland, Timor and Liberia. There is clearly a right way to do it, and that is what I would want us to do now.
Very notably it requires a focus on closing the books on past history, a final round of forgiveness/redemption, followed by a better path forward. Which is the exact opposite of the kind of justice that the reparations crowd is asking for.