And a somewhat controversial one.
A “Culture” often includes a religion.
And to use your pyramids as an example they show up everywhere.
Babylon and Egypt come to mind first.
But India and China have equally old pyramids.
And they all have some kind of recorded history, even if of dubious accuracy, to trace the culture that built them.
(BTW, In addition to pyramids, the same can be said for “standing stones” in straight lines or circles.)
But your Western Hemisphere pyramids seem to show up out of nowhere.
And interestingly, on the west coasts.
With no history to trace the cause of their appearance.
Is that because of trans ocean migration or just the local environment causing the records to rot away?
You can get passionate responses either way.