My mom mentioned that she saw the Exorcist in the theaters in the 70s and people were legitimately freaking the fuck out like running out of the theater.

I saw it much later in the 90s and the effects didn't continue to hold up compared to more modern movies, so it didn't really do much for me.

Kind of reminds me of the concept of Seinfeld is Unfunny where something is amazing at the time but then is copied by everything that follows, making it impossible to go back and look at the original in the same way.

I actually just checked, and sure enough that's an example listed.

The Exorcist: First-time viewers today can appreciate the film's quality, but likely won't be all that impressed because so many of the things that were new about it when it came out, the things that led many of the sellout crowds who waited on line for hours to see it even if they threw up and fainted, have been so widely imitated and emulated that they don't come across as shocking the way they did in 1974.