So I've been waiting for an opportunity to talk about this, and this thread seems like it. In my opinion, there's only one type of analog horror that's actually scary: Old-school public information films, like the Protect & Survive shorts:
This is scary because of who made it, why they made it, and the implications of it. More specifically: It was made by the British government and only intended to be aired if a nuclear war seemed imminent. If this was airing on TV and you were watching this, it meant civilization was probably about to end. That's an incredibly spooky concept, and it's been made spookier by the passage of time. The vintage feel and presentation makes you feel like you're peering into another timeline where the Cold War ended in a much more grim fashion, and reminds you that could have been
our timeline if things had gone slightly differently.
In my opinion, the entire genre of "Analog Horror" is simply various attempts to replicate things like Protect and Survive and the uneasy feeling they give you... and they've all failed. Because they're not actually real. You can't replicate the context it represents.