Why is Star Wars not science fiction?
Star Wars starts with the proposition that there is no connection whatsoever between earth and the “people” in the story... and then proceeds to make the main race in the story a race of humans that look exactly like us (even down to the different races we have here on earth), without any kind of explanation or background.
And that’s just the beginning, which to me is fantasy... from the beginning.
Then add in the purely magical “force”, and you are dealing with a story of Magic trumping Science. “Use the force, Luke. Use the force”.
Then add in a mix of aliens in which the vast majority of alien races have only a single representative... it just doesn’t look realistic, doesn’t look like it’s even trying to be. Its creator calls it a Space Opera, and to me that’s another word for fantasy.
Star Trek, for all its fantastic elements (and there are some) is not PRIMARILY fantasy... not in my mind. Star Wars is PRIMARILY fantasy... at least to me.
I could go on in more detail but I’m not an expert and it is all a matter of opinion, but in my OPINION Star Trek is SF, Star Wars is not.
And by the way, I enjoyed the last two Star Wars movies and thought them very well done. I particularly liked the way Rogue One tied plot elements together over a period of decades. It was beautiful. But not SF.
Thank you. Good answer.
“Although it does add in plenty of unbelievable elements (such as a galaxy littered with aliens that look more like us than we look like chimpanzees, our closest relatives)”
ST:TNG addressed this in one episode, discovering the origin of genetic material which was dispersed across the galaxy and mutated into the humanoid forms featured in the show.
“Star Wars starts with the proposition that there is no connection whatsoever between earth and the “people” in the story... and then proceeds to make the main race in the story a race of humans that look exactly like us (even down to the different races we have here on earth), without any kind of explanation or background.”
You have touched on some things that bother me about Star Wars. First, I will say that it doesn’t bother me that the human characters speak English, because certain compromises must be made to make the story more accessible to the audience (the use of a constructed language with English subtitles would be tiresome), but the naming of the characters as “R2D2” and “C3PO” blatantly uses a Latin alphabet, so it becomes harder to suspend disbelief and accept the premise that the story occurs without any connection to an earth-based history. That is only one example, there are other problems, including the coincidence of the same exact human races that are on earth, as you mentioned.
By contrast, I think the Lord of the Rings does a better job of creating a fantasy world where you can more readily accept the premise that the story and characters are not directly connected to our own culture.