Even in idealistic settings like Star Trek, you still have divisions and unification based wholly on race. Even in the federation, one of the things people learn is how to deal with "different" races because some races are more aggressive than others or handle insults differently etc... No one tries to pretend differences between races don't exist.
Race seems to be one of those things we implicitly understand to be a cause of unification or division, yet if one considers this reality in our culture, you're immediately labelled a racist.
The conservative ideal of race neutrality, as in we can just pretend race is a social construct and treat everyone the same, is a denial of reality. The liberal ideal of all races being equal, as in any differences is due to racism, is also a denial of reality.
Can we not just accept that races exist, they are different and then adapt our society toward this?
No one thinks perfect color blindness makes any sense, but treating human beings as individuals are a theme of the USA and of Science Fiction.
Even though you are a dirty stinking Centaurian, We can be best friends and defeat the evil whatever together....
But yes, like in Flash Gordon, no one ever made arguments like "I identify as someone with wings, you must admit that I fly."