>>281143090 (OP)It's made for a very small niche; the investment to replicate Miura's art would be immense—look at what happened with the Junji Ito anime—and, most importantly, there's very little margin for merchandise.
It's extremely common to see teenagers carrying Kimetsu plushies, keychains, or clothing. Can you imagine a doctor in his office wearing a tie where you can see Cazca being raped while he talks to a pregnant patient?
Anime are huge commercials, the money is in the merchandise, which is why Vampire Hunter D movies were considered a failure. They are artistically beautiful, but they didn't sell enough DVDs nor did they significantly increase sales of the novels.