Like most anything else, your survival bag should be durable and multifunctional to some extent. For example, a dry bag for your belongings can also be a great resource to collect tinder because of its waterproof capabilities. Lumbar packs can pack small necessities like your first aid kit, knives, and water bottle, which is ideal when you plan to travel outside of your camp for a couple of hours.
All in all, your survival bag should fit everything you need. The bag should be durable and comfortable to wear, especially if you plan to use it while hiking, hunting, or traveling for several hours. Lastly, your survival bag or pack should be multifunctional to some extent, where you can also use it for basic tasks.