Every generation has a story.
Why it is hard sci-fi
Soft. The films Starkiller Base is a planet-scale weapon that drains a star to fire, which the film acknowledges with a shot of the local sun visibly dimming. The energetics are still cinematic. The scavenger economy on Jakku, by contrast, is a working portrayal of how a downstream culture lives off a battlefield generations after the fight.
Science inside it
Stellar mass conversion as a weapon, post-conflict salvage economies, and droid-mediated information transport. The film treats the droid as a physical key with secret data on it, which is at least a coherent premise.