I think paths might be a big factor–I have an area that was pretty run down near the start of the game that I've cleared and made into a park. It has a path running through and I see villagers there all the time now, but before the path was there, it was a dead area.
Right now, villagers rarely go to the museum and campsite area. I've seen a villager by the museum like once, but I've literally never seen someone hang out by the campsite. There's no paths by the campsite so maybe that's a factor?
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