Ah, got it. I thought you were specifically looking for slower / slow burn movies. The Witch is definitely that, but if the period in which its set doesn't appeal, you would for sure find it boring. Personally, I loved it, right down to the archaic language. Midsommar was also a heavy favorite of mine, as was Hereditary. All three kind of hit that sweet spot of creepy for my tastes.

I'm going to catch Smile this weekend and hope it's right up that same alley!