Lately I've been trying to think of why it feels that Horror, of all genres, seems to have by far the biggest glut of low effort garbage
And I figured it out, though it's obvious: it requires the least amount of work to throw together a horror story. All you need is some kind of creature, or ghost, or whatever threat and people to get killed or scared by it. That's it. You barely need to put together a story.
Like every other genre requires a just a bit more of the barest minimum of thoughts. Not horror, though. (please note that this isn't a disparagement of horror in general, good horror rules)