I guess I'm showing my age by saying that this movie is the kind of thing that just wouldn't have gotten a wide release when I was young. Why? Because it's about cannibals, "eaters" they like to call themselves. They are people that eat real food, but periodically feel the strong urge to eat other people. As much as it sounds like sideways vampirism, they don't offer any supernatural explanation for it. The only "powers" they have is a sense of smell that lets them identify other eaters.
Thematically, the eating thing is a stand-in for any addiction. There is even a tertiary character who tells the main character that he reminds him of every addict he's ever met. As vague and artsy as that sounds, Chalamet seems to have embraced the concept. He is emaciated in this movie. When you see him, the first thought you'll have is: addict.
The strongest part of this film is the sense of place. The time is set back in the '80s, ostensibly so the characters could get away with casual serial murdering without running afoul of modern technology that might catch them. Every location is deep in poverty. It's shot and textured in such a way as to imbue the audience with a powerful sense of operating in this sub-world of poverty in the US. There isn't a nice location or even the barest sense of optimism in the entire picture. It was stunningly effective.
The performances were very strong. They were what kept me watching. The plot is rather asinine and the setup incredulous, but the way it was shot and the performances kept me immersed.
That's the problem with this film. There is enough there to keep me watching, but the pacing and plot didn't deliver. They didn't lead to a payoff. The movie eventually just ends, much as it begins, with a cleared-out apartment. In that sense, it's a vignette more than a story. All that's to say that when the lights came up, I was bemused.
And yes, they show people eating people in this movie. It's revolting in the extreme. Most importantly, it's not worth sitting through those bits in hopes of some poignant resolution or payoff. It never comes.
I don't recommend you watch this movie.