Define horror.

I think it’s folk horror. There’s horrific bits in it.

It's only horror if it has a Frankenstein or a Wolfman in it

It is. You're wrong. It's literally the pinnacle of folk horror.

I'd very much like to know why you think it isn't horror? I can understand why you attribute mystery/suspense to it, but that doesn't preclude it being horror. What are examples of movies you do consider horror?