I challenge you to think of a better airtight storage container than a 5 gallon bucket. They are the perfect size for nearly anything that needs to be stored secure from oxygen and moisture.
If a container is airtight, it’s also watertight. That’s a key factor because water is often more damaging than air. Too much moisture causes mold for instance, which ruins more than just food! I’ve seen a sleeping bag completely ruined by mold. Properly stored in an airtight 5 gallon bucket, that expensive sub 0 sleeping bag may still be usable today.