Gataca was a cautionary tale, not an instruction manual.
The actual technology of Gattaca has already started 50 years ago with the first "test tube babies" and IVF treatments. You get a "optical selection" of the most well developed blastocysts, checking for symmetry, growth rates, and other biomarkers, without even resorting to DNA sequencing selection.
It will absolutely make the world a better place long term - all of our children can be genetically "the best of us", according to various criteria. I'm all for it.