Killers of the Flower Moon is an extremely well acted movie of blah.
I always dislike comparing the movie to book as the book always tends to be better but I don't understand Scorsese's decision to reveal who the murderer is so early in the movie. The book was full of suspense because you had no idea who who was behind the murders. The federal agent Tom White played such an important roll in the book and he seemed like an after thought in the movie.
I felt like this could have truly been one of the all time great master pieces of cinema history if Scorsese had followed the book more closely and kept the suspense rolling leaving people at the edge of their seats trying to figure out who and why all these murders are happening.