Maybe not downside... rather, double win. First decade or decades, good business for those whose trust funds are invested in pharma. Following decades, planet increasingly depopulated so certain people's offspring will have a nice emptied planet and well-filled trust funds at their disposal. I think after they researched gene drive on /for mosquitoes... It is clear that they could get the idea of using that concept on humans, too. Would not be a far stretch. As so often, the real difference in intelligence (misunderstood by certain types) is NOT, to be intelligent enough to come up with ideas. All they are doing is not at all difficult to imagine. Real human intelligence means, being intelligent enough to DISMISS certain really rather trivial transpositions of methods for dealing with wares, and with animals, to dealing with humans.