[AstralStorm]

And why is modifying a human unethical, or more so than modifying any other animal which we do all the time?

Technically, there should've been phase 1 trials. How do you propose to do that otherwise with genetic modification of germline cells otherwise?

Someone will have to be risked, like with any unproven treatments.

Either you can ban human modification on shaky grounds (not really ethics), or you will have to take that risk to just see if modification can take. There is no third way, no amount of animal studies proves the technique works in humans.

You could test it on embryos, but then you have to either kill them or are back in the same place. And it does not provide complete information - only about relatively early development.