If I hadn't read anything that built on this book, it would probably be the stupidest book I've read. Not even interesting in a mythological sense cos it doesn't actually say anything about anything.

It uses that classic conspiracy weasel of "just asking questions", and as such relies on putting forth incomplete and inaccurate information to suggest mystery. Then they fill the gaps with aliens or whatever they please, because they've removed the falsifiability of their claims. Eg saying "a working battery was found with no knowledge of who made it" allows for any answers to seem somewhat credible and there's no way to prove them wrong, but saying "something that looks a little like a battery but that at best may have been able to electroplate things and the people at the time may have known how to do that" narrows the scope quite a lot, and also encourages thinking of other things it might actually have been for.

There's an enjoyable and informative podcast called "it's probably not aliens" that investigates claims made on the Ancient Aliens TV show (based on chariots of the gods etc). They sum up the majority of the claims as either racism ("it's not possible the egyptians/mayans/africans/polynesians/indians/etc made/discovered/imagined this") or "thing looks like a thing" ("there is an object/image/concept that appears to be this modern object/image/concept" without questioning what else it might be in context, which often makes it pretty clear). This is an accurate description of the thesis of the book.