Gotta disagree about the Mist.

The monsters absolutely were the point, and something like a storm/flood/fire wouldn't flip that many people to religious human sacrifice or electing a religious leader to decide who gets sacrificed within 3 days. (the reason she was being believed was also monster related)

The monsters are what caused panic, fear, loss of humanity, and desperation. The movie makes a point to illustrate this when the generator stops working - the people needed something they could understand, and resolve, and refused to acknowledge monsters would be possible until they see part of one and some flip from impossible to act of god/devil, which doesn't really happen with fire or rain or snow.

The variety, size, and mysterious origins of the monsters are absolutely the centerpiece and couldn't be replaced by any natural disaster, as the whole point was how unnatural everything became.

I would say that Prey isn't so much a monster movie as a movie with an 'ugly' powerful humanoid. I would definitely put "The Thing" on this list, but it's not exactly modern.