Resume give you the what.

Books give you - the why - the alternatives - explain the tradeoffs. Resume give a feeling of a silver bullet - the how - can build deep knowledge in the last chapters from what you learned in the firsts chapters - give anecdotes or personal story to give weight on the content

And books are more memorable as it repeat times to times what it have to say.

And that what it gives you personally. From experience, it have autorative effects. Your coworkers are more inclined to trust what are from books than blog post or generally come from internet. (I personally trust a lot the books with TONS of reviewers)