A labyrinth of passages hides it, but even Amenemhet III's grave was eventually robbed. This fact ultimately led to the end of pyramid building. No tomb, no matter how splendid, was of any use to the pharaoh if it was plundered and his mummy profaned. It was to no avail. Robbers, incited by the enormous treasure available, found every pharaoh but Tutankhamen, and stripped them of their riches.
Questions remain about the ownership of some pyramids.
Money for research is the biggest single impediment to finding any answers. The pyramids are still wonders, but there is no need to mystify them. Scientific Egyptology has found many answers to their mysteries, and not once has there been a need to involve aliens, Atlanteans, or any supernatural agency. The genius of the ancient Egyptians is manifest. The Ancient Engineers.