“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.
I agree about Lord of the Rings. But LOR is openly fantasy. Star Wars is fantasy pretending to be SF.