I still have doubts about the evidence for identifying it's builder as Kufu of the 4th Dynasty. But if it wasn't Kufu, I am inclined to be the opposite of most fringe theories and say I think it's younger not older then the traditional view. That it's absurd to think the most impressive Pyramids predate many inferior ones.
For one thing if you take Herodotus' account in the context of his full Egyptian narrative, it makes it younger than the Fall of Troy. His Cheops is later then his Sesostris who he identifies as the contemporary of the Fall of Troy.
I see the logic of how Kufu can become Cheops etymologically, but I still feel it's shaky. The big issue is when people use Manetho as a smoking gun on that identification. First off Manetho highly criticized Herdotus elsewhere, he hated his narrative of Egypt.
And who knows if these details were added by transcribers. These same transcribers have Manetho identify Memnon of the Trojan War with an Amenhotep, but Josephus makes no such reference discussing the same dynasty in Manetho.
When discussing the Fourth Dynasty, Manehto as transcribed by Eusebius says.
Of these the third was Suphis, the builder of the Great Pyramid, which Herodotus says was built by Cheops. Suphis conceived a contempt for the gods, but repenting of this, he composed the Sacred Book, which the Egyptians hold in high esteem.This can equally be interpreted as attacking Herodutus and saying this guy not his made up Cheops built it.
That account is interesting in light of claims the Great Pyramid builder wasn't following the normal Egyptian religion. What Archeology tells us about Kufu doesn't fit that legend however.
A quote attributed to Manetho, but that is not authentically Ancient is circulating the net saying the Hyksos built the Great Pyramid. This quote seems adapted from what Josephus quotes as it firmly misidentifies the Hyksos as Israelites. But Josephus doesn't mention the Great Pyramid. It doesn't even seem to come from the Book of Sothis which is at least medieval.
Theorists using this don't want to make the Pyramid younger though, so they attempt to say the Second Intermediate period Hyksos weren't the only Hyksos and that the 4th Dynasty Pharaohs were Hyksos too. They do this by misquoting the start of Manetho's Fourth Dynasty account "The Fourth Dynasty comprised seventeen kings of Memphis belonging to a different royal line. " By saying "The Fourth Dynasty comprised seventeen kings of Memphis belonging to a different race." See the difference?