I thought the Exorcist really suffered from this. Most of the fear comes from the symbols and satanic themes being taboo. If you don't really care about it then it becomes much less scary. I still think that creepy satanic cults can be scary though, the VVitch, Hereditary, and Anthrum all used the tropes successfully. I don't like the found footage gimmick in Anthrum but you gotta admit that hillbillies with a rusty, decrepit Baphomet figure burning a child alive in a satanic bronze-bull-esque contraption is pretty scary.