We want to go slow on the gene editing in real humans. For example, if we're talking embryos, we can just screen for the bad genes and do IVF for the embryos that don't have that gene, no need to edit the embryos in the first place. So that leaves the main use as being for gene therapy for already living humans, and since screening can be rolled out much cheaper and less dangerously than trying to hack the genome of already living people, there will be an ever-decreasing window of usefulness for gene therapies. We should still look into it, but providing mass screening would be far more efficient and less controversial than trying to edit babies*. Also, all that effort would basically be invested in making something we can already make for free: babies that don't have that genetic disease.
EDIT: *here's the main gist. Think about how many incidents of a specific genetic disease are prevented per screening vs per gene editing an embryo, vs gene therapies on an already-alive person. Then consider how much money each one costs to enact, and whether or not we have enough money to 100% roll out the solution. The basic screening technology would work out as the least-expensive option per number of cases prevented, so it's the long term best option to deal with the problem. Only once you have 100% screening, only then would it be worth investing any remaining money in the gene therapies, in terms of saving the most people.