The best "true crime" film ever.
Scorsese just made one of his greatest movies: atmospheric music, convincing acting, flawless plot, cinematography and directing are just perfect.
I honestly can't see any problems with this, except for the long runtime, which was not a problem for me at all. I enjoyed every second of the film, it kept me engaged and therefore entertained (!).
"Killers of the Flower Moon" is not just a regular crime story by Scorsese, it shows Native Americans, their culture and problems they faced like no other picture I've ever seen.