While there may be relevant information online, there are several downfalls to just “Googling” it. For one, it’s difficult to know what is reliable information, and what is opinion or conjecture. When reading a book, there’s an author biography that lists the credentials and demonstrates their credibility. Second, phones and computers die. If you’re in a survival situation, there most likely won’t be a plug-in nearby to charge electronics. Having a hard copy allows you to always access the information, especially when it’s most needed.