I like this deck a lot. And the book is often necessary because cards will depict gods and historical figures that aren't necessarily recognizable in sight.
But the book sometimes gets its mythology wrong, refers to worrying ideas like theosophical Akashic records, and tries to brute force a thesis about prisca theologica that's as unnecessary as it is culturally flattening. The book will often talk about how "all cultures" do something that's factually untrue, like believing in "the light."
It does feature a more systematic mapping of I Ching trigrams to tarot cards, which was interesting. And much of the myth and history is still good.