A lot of wacky stuff has been posited by a lot of wacky people due to the fact that pyramids were made by various cultures at various times, despite these cultures having had no contact with, or knowledge of, one another.
How could that possibly be? How could so many different cultures come up with the same structure throughout history?
This is how: Because all these cultures were made of people, and people anywhere think the same way as people everywhere. And the people that made up these cultures wanted to create the tallest, most stable structures they could.
And at the time these cultures existed, the pyramidal form was the best one to use to create a tall, stable structure.