Much as I hate the glut of sequels and reboots, this actually is not a new problem. Here’s a list of the highest grossing movies in North America, adjusted for inflation.
Of this list, Gone With the Wind, The Ten Commandments, Jaws, The Exorcist, Doctor Zhivago, One Hundred and One Dalmatians, Ben-Hur, and Jurassic Park were based on novels while The Sound of Music was based on a musical, Snow White and the Seven Dwarfs on a fairy tale, Avengers: Endgame off of a comic, Titanic and The Sting on history (albeit loosely), and The Lion King on a play.
Four more of these movies are sequels and (all in one franchise, at that), so we’re left with two movies (Star Wars and E.T.) that were not based on a pre-existing IP and/or history and were not part of a franchise. Also, two of the movies on this list (The Ten Commandments and Ben-Hur) were remakes of earlier silent films.
From the beginning of the film industry, adapting a novel or stage musical or play everyone already loves has been seen as a safer bet than an original screenplay and it’s worth noting that execs originally had little faith in the success of either Star Wars or E.T.










