Wait, how is it not supernatural? The show literally ends on a debate between two supernatural beings about whether the do-over current-Earth version will avoid repeating the cycle when their technology gets advanced enough. There is zero question that they're supernatural. The text says it outright. And it's not a hallucination or a fakeout or a technological artifact, we get an omniscient POV showing us this, it's not filtered by the views of a character.
Hey, I also wanted it not to suck, but the text is what it is.