Warning: This post contains spoilers for Foundation, which was first published as a single book in 1951.
In my opinion, modern science fiction was invented by Isaac Asimov with the publication of Foundation. Foundation is about the fall of the Galactic Empire and the establishment of the Second Galactic Empire. The book takes it for granted that the establishment of a "Galactic Empire" is good for humanity because it reduces violence.
Isaac Asimov got the idea for Foundation while reading Edward Gibbon's The History of the Decline and Fall of the Roman Empire. Imperial histories tend to be written by the beneficiaries of empire. No one wrote The Death March to Rome because slaves didn't have paper.
But the bigger blind spot with Asimov's writing—and this is a consistent pattern across science fiction more broadly—is that oversimplifies politics. Jane Austin he is not.
Subsequent novels didn't do much better. Brave New World is about progressivism. The Fountainhead is about collectivism. Starship Troopers is about fascism. The governments consistenly implement coherent ideologies—something that never happens in real life. Nineteen Eighty-Four does capture subtlety, but even O'Brien is mindless slave to an ideology. Science fiction needs realistic politicians to pursue complex interests in an arbitrary world. It isn't until you have a model of reality reflecting the complexity of human society can you even begin to comprehend the causes of things like sexism.
Ancillary Justice by Ann Leckie has a realisticly complex government. It has slaves. It has aristocrats. It has genocide. It has factions. The protagonist shoots priests and freedom fighters. It has foreign affairs. It has insurgencies. It has foreign interests arming an insurgency.
Ancillary Justice is a masterpiece of science fiction. The artificial intelligences feel artificial. The aliens feel alien. Its handling of sex and gender is (to my knowledge) unique.
Ancillary Justice is translated from a future language without gender-specific pronouns by an AI that has trouble distinguishing humans' sex. It is the opposite of what Asimov did. Asimov wrote men and women the same and then let you know who was who. Ann Leckie writes men and women as men and women and then doesn't tell you who is who. Gender matters in Ancillary Justice because Ann Leckie portrays realistic politics. By forcing the reader to do work to figure the genders of the characters, Ann Leckie forces the reader to think hard about when gender does and doesn't matter.
But my favorite thing about Ancillary Justice is its government. Science fiction has a tendency to ignore communication delays. In Ancillary Justice it takes weeks (months?) to transmit a message from one end of the empire to the other. This affects internal politics.