It's time for the protagonist to sloooooowly step into the hall...time to have the camera zooooom in on her faaaaace, ^(time for everything to get reallllly quiet, as she sloooowly walks forward, eyes darting back and forth, all you can see is her face, silence, you can hear the other people in the theater chewing on their popco-)

LOUD NOISES FLASHING LIGHTS MONSTER FACE!!!!!!1!!!!

Hah! Everyone jumped! That means they're scared! The movie is scary!

No.

Pretending that getting people to jump means something is scary is like a comedian going out into the audience and tickling them to get them to laugh. It's a physical reflex, it's not your movie or game or whatever achieving its intended effect.

The bad thing is, so much of the horror genre seems to rely on jumpscares. Getting startled isn't entertaining, it's annoying. Even good horror, horror that actually achieves what it should, in that it gives you a story that haunts you and lingers with you and gives you chills, even things that can stand on their own seem to follow the trend of throwing in jumpscares. It'd be like if every comedy movie hired ushers to sneak around the theater tickling people from time to time so they'd laugh. Laughter doesn't equal funny, and jumping doesn't equal scary.

Jumpscaring is something your little brother does when he's bored to annoy you, not something that belongs in professional writing pretending to be horror. Writers should ditch this trend.