Coming from long line of Mormons and pioneers, i think this is still good topic. Are backpacks worth having for "prep"? Yes, but for purpose. From experience I have some advice on rucks/packs, conditioning, and why they are important: https://twitter.com/HoggWood/status/1319085538155036673

First if you are looking to buy, I recommend Varastruleka. Very affordable rucksacks, good customer delivery, solid quality. If you have old Northface, this is fine.

BUT assess your reason for wanting to use one. Rucks/backpacks are incredible but limited. I'm in Hyperborean shape and even I would struggle 7+ days with no extra foraging, hunting, etc with what I can pack out. And no, fish aren't enough.

Unless you are experienced hunter, have done 50+ mi w/canned food, or are using it to get to a cabin/property, I would recommend getting in backpacking shape BUT invest in transport and land. Like @braxton_mccoy said truly: you'll starve.

Backpacks/rucks are good for: moving from point A-B, foraging, extending your range from home base. It's delusional to think you could live from backpack and hunt...all on foot. Hunters and outfitters use horses/mules for this purpose.

Go out on the weekends and practice your bushcraft, build back muscle, but even better: make frens out on these trips. Hone your ability to communicate and forge bonds. Sounds cheesy but it works. Call it networking, whatever...

When collapse comes, it will be your tribe and frens who will be worth the most!