Not much of a revelation, just an observation, but how much of sci-fi pushes the ideal that Humanity's path forward is unification?

Star Trek is a major one, and many would state it was a progressive show, and it earnestly was.

It also stated that in its ideal future, there's a Federation of like-minded extraterrestrials, and as a member species, Humanity lives in a united, post-scarcity society under a single government.

To that end, how many alien species in these stories are so inhuman, in that they have no differences, a world-wide government, a single language?

It's laughable how direct the propaganda was, and continues to be.