When we're talking about this kind of genetic manipulation, there's two methods. Being able to meaningfully read a person's genetic code (we do not understand the majority of a person's genetic code due to a variety of issues), or basing your actions on individuals.

The individuals version has already been done, where we barred certain 'undesirable' individuals from reproducing. We know this one to explicitly only leads to evil implementations. It turns the practice of finding a romantic partner into a game of fusing two people together to get a better one.

The other method currently has two tools currently: selective IVF and CRISPR. Both of these are in their infancy, with how effective they are still being up in the air. These techniques require highly specialized professionals and are thus expensive. These will likely always be expensive even after they get cheaper. The world we live in where the rich can have "super-babies" with no genetic defects, while most poor children are still born naturally, is one where discrimination based on genetics is treated as rational, and based on lineages. That is fundamentally the creation of an evil world.

We're also still ignoring the fact that we're still pretty explicitly ableist as a culture. How do you think it'll feel when a person who lives with a disability gets pressured into IVF "so the child doesn't end up like you". Blind people have a subculture, deaf and mute people have a subculture, most people living with disabilities find each other for solidarity and relatability. We call it 'living with disabilities', but they just call it 'living'. We're still treating these issues as if they're something to wipe out rather than changing our culture and infrastructure to accommodate them.