I wholeheartedly agree. The geological and architectural evidence is conclusive.
Even a mainline Egyptologist (I can’t remember his name, the book is around here somewhere) points to that New Kingdom copy of an Old Kingdom record — which states that Khafre repaired the Sphinx — and the fact that the causeway to the Khafre pyramid was built to avoid the Sphinx enclosure, and attributes the Sphinx’ construction to Khufu. Right idea, but wrong date.
Another suggestion has been that Khufu’s successor — Djedefre, elder brother to Khafre — built the Sphinx, but there’s pretty much no ancient evidence for that, and Djedefre started construction of his pyramid at Abu Roash. The site is now protected, but in recent centuries the unfinished structure was carried off by the camel-load to build stuff in Cairo.
It’s a fascinating thesis just how far back it goes. Something to consider that if it goes as far back as 5k, we are closer to Moses than we are to the builders of the Sphinx.