It's easy to see why people would dislike this. It really comes down to taste, not anything wrong with the movie.
I haven't read the graphic novels, so I'm only going to base anything I say off the movie. And I really found this to be a good blend of real myths, real philosophies, real cults, and horror tropes.
Yes, it might come across as borrowing from anything and everything, but that actually fits one of the philosophies discussed by the cult: everything is connected and is the same.
I enjoyed the score; it underpinned how scenes should be interpreted without TELLING you how to feel like many tense movies do. The lighting and camerawork helped play out the story, and the set design gave a grimeyness that made the evil seem more ancient. Good dialogue and good acting. Definitely a slow burn that takes you were you need to be.
A little bit Call of Cthulhu, a little bit Wicker Man, a little Vanilla Sky. Just a little bit of a lot of somewhat cerebral horrors. Not a fast-paced jumpscare teen slasher flick by any means.