In my humble opinion, despite creationists best attempts, and attempts by the many bible redactors who edited the early stories in Genesis, there is no telling just how far back in earth years were the “ancient” ages in human history. I leave the facts of it as a question only G-d knows the answer to and one that if G-d thinks we all should know it, then G-d will make sure we do.
I have read a number of Hancock’s books. I accept his premise that humans have been around, and even “civilized” longer than folks in the last 2,000 years believed/believe to be the case, but beyond that premise I have always found Hancock to often be a speculator on many facts of it all. Take the premise for whatever you want, but have some skepticism for the details no matter what you think of the premise.
I can’t disagree with what you wrote.