Considering this year’s Hugo winners on the TVTropes Mohs Scale of hardness for SF, Thomas
Olde Heuvelt’s short story “The Day the World Turned Upside Down” rated about 1.0. It used a science fictional setting as an allegory for breakup of a relationship. In this case, gravity reversed so everything flew off into space. The protagonist journeyed through this world turned upside down, meeting other people who seem to be in dire straits, and still failed to patch things up with his girlfriend. If I haven’t already, I have to admit that I like literary stories. I enjoyed the allegory and the subtext, but it wasn’t really science fiction in the sense I’m discussing here.

On the other hand, Cixin Liu went for the 5.5 with his novel The Three Body Problem. Not only does he set up a complex science fictional “what if” situation revealed through an online game, but he uses the narrative to ask questions about how we would proceed if the “what if” situation of aliens arriving in the solar system ever really came to pass.

Both these were deserving stories in their own way, but my whole point in this discussion is that very few people these days seem to make the effort Cixin Liu has made 1) to actually translate subjects like orbital mechanics for the average reader and 2) ask questions about the future of the human race.