The danger of letting parents choose modifications they think will serve their children in life is exactly what Bashir expresses in DS9: it gives parents, and society more generally, the power to determine what’s acceptably “normal” and flatten out anything that deviates. Geordi similarly expresses at least twice that he doesn’t want normal vision, that his blindness is not a defect that needs fixing and what’s utopian about the Federation he lives in is that his difference is accommodated and supported.

I’ve always really appreciated Star Trek’s hardline stance on this, because its a moral problem that I feel we’ve lost a little bit of sight of and is going to emerge again in the next few decades in real life. I think you could make a case for the Ilyrian environmental adaptation being different, but to do that you would have to explicitly place it against the real arguments against gene editing and work through them, and this episode went in a different direction.