Sci-fi tends to reduce all planets to monolithic cultures or two at best but it seems more likely each other planet would be as rich as our own with different languages, religions, cuisines etc
@anon_opin It's not that unrealistic though, some planets could be relatively new colonies with 1-2 dominant cultures. Guess depends entirely on what sort of universe setup it is. Like, I can imagine a galactic federation or empire sees planets like individual regions and interplanetary dependency made people identify more with their planet like people do with nations today.
@anon_opin it’s maybe realistic depending on how difficult interplanetary travel is. Entire planets with a monoculture are just the natural extension of people wanting to live in a bubble of people who think the same as them, although it does raise some moral issues around any children brought up in those cultures believing it’s the only option.
