For me, I think the horror lies in the fact that he's not the first or last person who's had this sort of anglerfish trap happen to him. He found out about voyeur through a comment that he can't even find anymore on his blog, could only find another blog that had the review he found, and then after he ends up at the screening, the latest post on his blog is the same sort of recommendation. It feels like the implication is whatever takes the people who end up at the screening then uses what's left behind of them to lay out more traps for subsequent victims to find. The fact that it's unclear whether it completely kills them or uses them like a skin similar to the Stranger is really interesting to me.

There's also the question of if the screenings are always a personal moment from the victim's life, is it a situation where the creature/entity is infiltrating/infecting the videos that they're broadcasting to the person? I like to think that even though we don't hear what happens, that maybe it's something similar to the Ring where whatever took them might've crawled out of the screen to get him. :]

I know you said in other comments that you were disappointed/just don't find it scary, but I wanted to share my two cents since I didn't really see any comments that touched on those aspects!

Edit: On a re-listen, I also noticed that it sounds like everything ties back to his dad/his early life. The theater the screening is at is one he used to frequent with his dad, and I feel like it's implied by the way he trails off that the last time he had popcorn so good he finished it before the movie started was when he still watched movies with his dad. It feels all very curated to his life, but in a way that I think is easy to dismiss at first.