> Saying it's not sci-fi because the fictional advance is set in our past (but at a development technologically beyond our own) seems quite a strange distinction.

I didn't say that at all. It is in the past, and also, it is not science fiction. Star Wars is quite fantasy, offering no explanation in science for the force, hyperspace, lightsabers, etc.

I love Star Wars with all my heart. But it is not about the future and it is not science fiction. It takes place "a long time ago" and it centers around magical, unexplained powers.

Edit:

And,

> Isn't the key part of Sci-fi that it contains a society that has in some way advanced beyond our own?

No, I don't agree with this at all. I would even say that in nearly all science fiction published, the societies have not advanced beyond our own that much - or if they have, they are also demonstrated to be far behind us in other ways. Science fiction is a lot of things, but certainly there is no requirement for it to show a more advanced society than ours.

No. The key part of SF is the "What if...?" question. A Science Fiction story should posit a difference about the setting from our own world and this difference should have consequences. Alternate history stories like "The Man in the High Castle" are Science Fiction. "What if the Nazis won?".

Likewise the key part of Romance genre fiction is the Happy Ending. It doesn't matter whether they sleep together (a lot of Romance aimed at older and Christian readers doesn't have any sex at all), or get married, but there must be a Happy Ending.