Some movies are big, and then there are movies that feel like they arrive with their own weather system. James Cameron’s sci-fi epics belong in that second category, where every new chapter comes with years of anticipation, impossible box office expectations, and the weirdly reliable spectacle of everyone asking whether audiences still care, only for the answer to be “yes, obviously, look at the money.” After another massive theatrical run, the latest trip to Pandora is finally getting ready to land on streaming.