[Star Trek] Why did Starfleet and the UFP as a whole ban genetic engineering?

I’ve never really gotten much of a clear answer of the ideological reasoning. I get that humanity in universe had issues with gene editing and Khan Singh and supermen but why does that make the lesser stuff completely banned?

Are you telling me the Starfleet and UFP commitment to diversity and fear it’ll lead to beauty standard messes are so severe they just throw the baby out with the bathwater? Refuse to ever mess with gene editing on sentient beings for worry it’ll go wrong inevitably?

I don’t get it, any help is appreciated.