Twenty-three minutes is not a book in the ordinary sense, and it would be dishonest to present it as one. How to Hack is the short piece of non-fiction carrying the name J. D. Rockefeller in our catalogue, filed under science and engineering, and the running time sets expectations more accurately than any blurb could.
Very short non-fiction has a legitimate purpose. It exists to define terms, sketch a landscape, and hand a newcomer enough vocabulary to ask a better question next time.
What it cannot do is teach a craft. Anyone arriving with the title taken literally will want something considerably longer than this.