It’d be really tough to figure out who is an ancestor of an enslaved person, and who isn’t. And even if you did, things would get weird. You’d have what we consider white people now, who’ve been “white” for generations, getting slave reparations because of their great, great grandpa. You’d have some ancestors of the slave owners, getting reparations. It’d be weird. Plus, the whole “sins of our fathers” issue.