Daddy-O of the 7 Wonders on Nostr: What's the difference between embryo selection and raising a bunch of kids and then ...

What's the difference between embryo selection and raising a bunch of kids and then just killing off the ones you don't want (IQ too low, has peanut allergies, wrong eye color, wrong sex . . .etc.)? So long as it's done before a certain age, like 5-years-old, would that be morally acceptable?