It hit me that the author, who presumably did a lot of research into the industry in order to write the book, is basing his book on the idea that crypto has collapsed permanently after having a short moment in the mainstream in 2021 (though you coulda said the exact same thing about 2017).
I almost laughed out loud cuz here is an author that did enough research to write an entire book, far more research into the space than the average person does, and even the author doesn't understand what anyone who actually participates in the market easily understands - that the market is cyclical and the 2022 crash was not an end event for the industry but simply the end of a market cycle leading into the next larger market cycle.
This is about how a writer understands and knows the bitcoin journey process and maybe the book you are looking at still has other connections. But he didn't explain the bitcoin process completely in just one book because the author's habit is usually to make readers come back to wait for the release of the next book and this is just my assumption. But if he says out of thin air that bitcoin has irreversibly regressed or collapsed in 2021, then I conclude he's not one of the authors worthy of being a favorite.
Why do I say that because he is too lazy to look for references regarding sources regarding Bitcoin's journey from when it was created to the process of its journey in the market until now. We know the four-year cycle in bitcoin and but to say that crypto in general has experienced a collapse is also wrong because the industry is basically growing.