Since being first exposed to these Hancock and similar video's on here 3 years ago, which I found both interesting but cautiously skeptical of, from just randomly listening to other podcasts and history books I think I have enough of a big picture view to put a rebuttal together. How I see it break down on his tow main topics is:
a) Geology work, primarily focusing on a massive meteor impact hitting the ice sheets in North America around 11,500 years ago - good solid work.
b) All the early advanced/lost human civilizations stuff - a massive stretch that's both highly unlikely and unnecessary.
So I'm focusing on b) here. Generally for civilization to begin you need human to transition away from the nomadic hunter gather lifestyle and towards a sedentary agricultural one. To achieve the latter you need 3 things:
1) a stable climate conductive for agriculture.
2) the necessity to abandon the hunting lifestyle and focus on putting that human brain to work at converting gathering to agriculture.
3) a good plant base source, that can be converted to agriculture and provides enough nutrition/protein in your primary diet.
The first is really a climate science thing and is all about the geological epoch known as the Holocene, which the Earth transitioned to coming out of the last ice age about 11,650 years ago. The Holocene is critical in providing the stable and reliable climate that allowed agricultural societies to emerge and human's to expand & thrive. Through most of Earth's geological history the climate wasn't so kind to us.
Next, if you're a tribe with plentiful game to hunt that's going to be your prime source of nutrition and is far more effective than early farming. It's when you no longer have enough game to hunt and you can no longer just migrate somewhere else because now there's people everywhere that you really need to turn human ingenuity to farming which is far more efficient once we figure it out.
Finally you can combine this all to see when where and how civilizations emerged. Wheat and rice are great sources and easy to convert to farming from the start. I don't know if Africa when you get to the savanna's and jungle really has a good natural staple grain, but more importantly game was always plentiful for hunting. In North America you had a late start because human's first had to cross the Bering Strait and then begin populating southwards, and corn was not a good starting grain. It took a lot of work to make strains of corn good for farming and they initially had to be combined with beans to get enough nutrition. Civilization was starting to follow the common patterns though in central America when the much more advanced Spaniards arrived and toppled everything over.
So basically while Hancock has some points of interest there's no need for an early advanced civilization that good wiped out with all evidence destroyed by his big meteor impact, and the emerging understanding of climate and human advancement makes it unlikely to have existed. If you look at some key points of commonality around the world, astrology is pretty simple as we're all looking at the same sky. Humans can be intelligent and curious, let us settle in the same place long enough not having to worry about our next meal and we'll figure out the same celestial cycles. In terms of construction with pyramids being everywhere, this is just a matter of physics as it's the most basic structure an early civilization can build that will also stay up. You don't start off building fancy Cathedrals that embrace your culture's uniqueness, pyramids are just logically the common starting point once you have enough excess manpower to start cutting and hauling rocks.
So overall I'm not an expert here trying to make a full rebuttal of this stuff, this is just my starting point for understanding why actual experts working in the field will scoff at this stuff rather than jumping onboard. I've always had a sense of 'this is highly interesting and sounds reasonable but their has to be a significant "but" in here'. I mean if you're a legit archaeologist/geologist/etc had good solid evidence of finding an advanced lost civilization that predates current human understanding you'd get famous off it.