Is it though? Time and again it’s been shown that having a very wide basic genetic options is the healthiest for a species. Evolution favors adaptability.

Depends what you select for. You could breed for intelligence, strength, etc and still maintain a diverse gene pool. Look what we’re done with dogs, ffs. It’s a scientifically valid practice. It doesn’t matter though because there’s no ethical way to do it.

Now if you’re talking about weeding out and genetic issues, diseases, and known problems, yes. We do that today.

Through gene therapy, yes. Eugenics implies selective breeding.