Vigorous mask-dropping very early on in the post:
The term "eugenics" has absorbed so much baggage over the last century that it somehow refers both to swiping right on Tinder when you see an attractive person and to the holocaust.
Not all dating is done with reproduction in mind. What are members of the opposite, or indeed same gender: baby synthesis apparatus? Unless you go out of your way in selecting blue eyed, blond haired people, restricting the definition of beautiful to these people, and restricting the teleology of tinder to the begetting progeny, how is it even remotely eugenics?
EDIT: Uncharacteristically for LW the post, was very short short, "very early" is actually about midway in a proposal of little substance, also choosing attractive partners doesn't guarantee ensure children anyway (unless using very specific definitions of beauty).