Everyone says germline editing would reduce diversity in the gene pool, and I can see validity to that argument. But, could it not do the opposite when people start altering their children to align with their own values? I could see the loss of some universally "bad" genes, but a lot of the judgement on this sort of things gonna come down to who does the gene editing and how they exactly implement it. When multiple groups start doing this in practice, I could see it fracturing the species more than homogenizing it. Especially when combined with something like iterated embryonic stem cell selection when you can jump several generations at a time. That would result in multiple post-human species derived from baseline humanity with their own specializations, talents, etc. Which would be more diverse.