I've just come looking for a thread about this, having this moment finished the last episode and been so moved by the final scenes I just wanted company.
I'm white, BTW, and definitely one of those who knows the sins of the fathers, so in one sense it was preaching to the converted, but there's always so much more to learn.
As well as the incredible scenes of Jackson's ancestors' tribe welcoming back their lost son, I found much of it very informative. Eg like Farle29, I'd had no idea of the scale of enslaved people being taken to Brazil, and like TooTrueToBeGood, the sheer number of those who died at sea.
I think sometimes programmes by white British researchers and presenters get a bit sidetracked by the guilt – either overwhelm or avoidance of it. There's a danger they either focus exclusively on the slavery of the British Empire, or it can feel like they're veering into whataboutery. This series, by an African-American, a Black British person and a Canadian, together with a black diving group (American?), avoided those grooves.
I had to watch in short chunks to take it in, but I'm better informed for having done so. Not just about the facts, figures and places, but about how important people felt it was to know where they came from.