Although freeze-dried, survival food packets should constitute the majority of the food you carry in a bug-out bag or 72-hour kit, you should also make sure to pack many of these high-energy food bars. As full of nutrients as emergency food packs and buckets are, if you read the labels carefully you'll notice they are kind of low on calories.
For supplemental calories high-energy food bar are perfect when you need a boost - you just can't beat the calories per pound. They are also high in electrolytes, and minerals which a prepper's diet may be lacking when facing a survival situation.
Lastly, unlike store bought protein bars these survival energy bars can withstand extremes of temperature. So combined with a 5 year shelf life you could safely store these in your garage, knowing they are ready when needed.