Hello! Author here! The book introduces a lot of tools (~20) and these tools are bound to get out of date eventually. As a matter of fact, the Babel libraries moved from v6 to v7 during the writing process, and I've had to painstakingly rewrite most of the book to keep itself updated.

But the core value of the book is not in the tools themselves, but the concepts and principles of these tools, and how these tools work with each other. And these don't get outdated as easily!

You think so? I figured maybe 10-20% of it was out of date, but that it was still probably worth buying. Still looking for alternatives, but considering it.