I've been alive for nearly 59 years and I've been deluded most of them.
Even with my delusions I've never witnessed anything close to what happens in demon movies.
I also watch a lot of movies.
I embrace reality.
I don't try to hide from it with delusions anymore.
My comfort now comes from reality instead of delusion.
Religion teaches fear.
I do not fear the world in which I exist.
Not anymore.
there is more to this world than that what meets the eye.
No, not really.
Delusion is not reality, it is a lie.
If you wrap up your view of the world with lies and fears, your demons exist.
If you can comprehend the cause and effect of reality, there is no reason to fear because belief in a lie is not required.
Back to movies, the priests who battle demons always endure a battle.
The demons are always super-powerful.
When the priest finally excises the demon, it is because of some special power granted by their God at the end.
Why does it take so long, why is there always screaming and yelling in a whirlwind of turmoil, why the flopping around and mysterious mutilations?
Because it scares people.
It makes money for the production.
If you read the OP you can see the reference to movies.
The correlation of movies to interest in those demons.
Those demons are fictitious, a fabrication.
It implies those demons exist as depicted.
A chain of belief based on a lie, just like religion.
Based on the movies you can see
The Warren's Occult Museum
http://www.atlasobscura.com/places/the-warrens-occult-museum-monroe-connecticut
A real world delusion reinforcement.
You cannot tour in person. There are special events and you can purchase or rent a video tour of the collection.