Please consider that a decision NOT to change genetic material of "germ line" cells may be because humanity decides it would actually cause a decline of humanity, not an enhancement.
Real social, economic and political factors are going to come into play here. As the author concludes: "Gene editing raises the spectre of parents making choices that are not obviously in the best interests of their children. Deaf parents may prefer their offspring to be deaf too, say; pushy parents might want to boost their children’s intelligence at all costs, even if doing so affects their personalities in other ways. And if it becomes possible to tweak genes to make children smarter, should that option really be limited to the rich?"
Real social, economic and political factors are going to come into play here. As the author concludes: "Gene editing raises the spectre of parents making choices that are not obviously in the best interests of their children. Deaf parents may prefer their offspring to be deaf too, say; pushy parents might want to boost their children’s intelligence at all costs, even if doing so affects their personalities in other ways. And if it becomes possible to tweak genes to make children smarter, should that option really be limited to the rich?"