We would need a very particular set of conditions for embryonic editing to be justifiable under a medical dogma that aims to "do no harm." Both parents would need to carry a large common set of recessive deleterious alleles, as this would make embryonic selection of non-carriers very difficult. Then we would need the editing system to be so reliable as to not introduce off-target mutations. In a preimplantation setti…
The problem with not editing the germline, is that that could easily be used to implement a DRM scheme. The recipient of this sort of editing might have a very high chance of only producing disabled or dead offspring, as they themselves would have been, without intervention. They, and their descendants, would have to procure this same treatment in order to procreate.
What is really happening is that normal copies of the human genome are being incorporated. Which are then passed on to your sperm/ovum.