If you're looking for survival rules, this is far more of a "Monster Hunter" style thing. It's not going to tell you how much meat you got after killing a tarrasque, but it will absolutely tell you what kind of weapons and armor you can craft from its hide, what abilties those items have, and the like. Even weaker monsters sometimes have materials that can simply be sold for money. It even gives ways to craft DMG items using certain monster parts, like using spines to make +1 arrows.

I would advise only including these rules if you want the game to focus around this kind of elbow-deep hunting and crafting. If your players want to wander the wilds and hunt monsters Witcher-style, then these rules make your life a lot easier.

Also, keep in mind that this book only covers the Monster Manual; Volume 2 covers Volo's Guide to Monsters and Volume 3 covers Mordenkainen's Tome of Foes. The main disadvantage of this book is that you're kind of restricted to using the official material unless you want to come up with loot tables for all homebrew monsters you want to use. But that's a "suffering from success" problem, and reflavoring things is part of D&D.