What is the most horrifying non-horror film ever made?

I'm talking about films that have little to no elements related to the horror genre. I would say Schindler's List due to the way it accurately shows the horrifying nature of the horrors of the holocaust, and the way how real-life evil is shown in the film. One of the best films that I won't watch again. via /r/movies https://ift.tt/3i5Hbel