I think any work that tries to compress all of the worlds human history into short digestable points is going to have to simolifynthings in a way that doesn't satisfy academics in various fields. It's an enjoyable read and has some food points to make.

Would I consider it an accurate reference material? No, but I don't think the author would want me to, either.

It's like freakonomics. It is both true and not 100% accurate at the same time.