I agree to a point, but Mad Max is an example of something original that seems to have come from a place of creativity instead of a committee and yet is still doing poorly.
So I don't think it's just that Hollywood has a tendency to do remakes instead of original stuff.
Just because it's a sequel doesn't mean it's derivative. All 5 movies are directed by the same guy. I can't speak for the first 3, but if you saw the 2015 movie and couldn't tell that it was a passion project, then I don't know what to tell you. We don't call Sherlock Holmes soulless even though Doyle wrote over 50 short stories starring Holmes.
It's entirely possible for someone to be creatively invested in a world they've built and want to keep exploring it in future works.