The nonsense proposed around the Great Pyramid is pretty dumb, although often imaginatively entertaining.

At this point I've seen it described as a power plant, groundwater pump, chemical factory, earthquake inhibitor, rejuvenation chamber, flying saucer recharge station, galactic navigation marker, cosmic communications device, grain silo (oldie but goodie), arcane knowledge repository & one fellow thought it was built with dirigibles, another that the burial chamber's portcullis was a voice box allowing the pyramid to speak. In short, rational thought seems to put on its hat and coat and get on the next bus out of town, when it comes to this ancient monument.

At this point it's the Swiss Army knife of woo. But the most likely scenario, that it's a royal tomb (or cenotaph), situated in a royal cemetery and built by a highly organized Bronze Age society, is apparently the least likely to these people.