Nicolas Tesla* somehow figured out "why" pyramids were found everywhere and why there were so many of them. In times long past...by harnessing the Earth's magnetic aspect...free energy was available. The obelisks were merely transmitters permitting the electrical charge from the pyramids to propagate even farther. All one needed was a receiver and an electric motor for power and off one would go flying or traveling across ground or water. Tesla discovered as much but his offer to mankind for such free energy in the 20th century was refused.
*Why Telsa's work has been largely ignored hasn't been explained.