The animation, the action direction, the music, the voice acting, all of those are top notch, and I dare say perfect. When the anime aired, the manga sales skyrocketed, and demon slayer became a gigantic cultural phenomenon. The mugen train movie instantly became the highest grossing anime movie of all time. And the entire 2 next seasons were even better.
"But the story is boring mid trash"
Which makes it that much more impressive that the anime is so successfull. When the manga being adapted is nothing special, but the anime is great, the adaptation is excellent.
