I don’t really appreciate jump scares in horror movies that much. It’s hard to articulate what makes a horror film “scary” to me, and it’s probably different with each one.
For example, I love John Carpenter’s The Thing because the atmosphere of claustrophobia, isolation, and paranoia is so pervasive that it becomes legitimately terrifying, and the few jump scares in the movie actually feel earned. That is probably my gold standard for horror, but I also like some slasher movies for very different reasons - usually suspense and thrills, even if they’re not really scary.
I guess the story and character development of The Exorcist were excellent for me, but the atmosphere didn’t creep into me the way it does in the similarly-constructed horror movies I’ve enjoyed, and it seems like that was the primary “horror” part of it.