Canned stuff will keep even with no power.
And the canner needs a supply of heat that can be even a camp stove.
I knew a couple who went to Alaska for the summer and he was an avid fisherman and she canned up lots of salmon on a pressure canner on their camp stove.
Yep, understand - that’s the big benefit, no power needed. Obviously the drawback is the overall cost, in order to build up a supply for several months!