Of course he's correct. I can basically destroy an logical argument to the contrary.
Human beings are AT LEAST 200k years old in modern form. That means you take a homo sapien sapien from 150k years ago, dress him up in modern clothes and give him a shave, he's exactly the same as we are today. Same brain case, same everything.
You're going to honestly argue, and academia does, that advanced* civilization hasn't risen and fallen several times in those time periods between us and 200k years ago? Gimme a break.
Written history, the vast majority of what we know, happens from about 6k years ago until today. And it just so happens, that the greatest mass extinction event of large animals since the fall of the dinosaurs happened LITERALLY in the backyard of our own written history, the Pleistocene mass extinction event. Gee, wonder if that has something to do with he fact human beings don't seem to have a history beyond Sumer and that it "starts" 6 years ago after 190k+ years of history prior. What were we doing that whole time prior? Why do know almost nothing about what human beings are doing culturally.
Everyone should do a thought exercise and for a second forget the nonsense idea of overkill theory by humans...which is nonsense of the highest order. Over 100 species of megamammals died in the Pleistocene mass extinction event roughly 12k years ago, that's for animals over 125lbs in body weight. The American Lion, Short Faced Bear, Ground Sloth, Mastodon, Wooly Mammoth, Wooly Rhinocerous, etc...all of them died in a period of time so short they couldn't reproduce. The amount of species loss of animals over 125 lbs in body weight is the equivalent to the amount of animals over 125 lbs in body weight that still exist today. Yes, we lost half of the species on earth that weighed over 125lbs in body weight...in about 1000 years (some existed on for a time in diminished number and small populations). Now consider what sort of event has to take place to cause something like that.
The answer is pretty simple to honest brokers of information. The world got SERIOUSLY fucked up between 12,800 years ago and 11,600 years ago. Nobody disputes this...the Younger Dryas was a 1200 year environmental and extinction level catastrophe.
So yeah, without getting into the weeds, Hancock is almost certainly correct. The question is to what extent did civilization rise?