Smart food preservation focuses on preserving the nutrients. It doesn't matter if something has a long shelf life. So does paper, and most paper is edible. But it doesn't provide the necessary nutrition for a healthy human.
The purpose of preserving food is to increase the shelf life while maintaining a high nutritional value. Most modern processed food fails to do this.
Traditional cultures knew how to preserve foods in ways that would increase the digestibility and nutrients. This is an area of great interest to me that I continue to study.
Each preservation technique has pros and cons. Some work better for certain types of foods or in certain climates.
You can also try using a root cellar for off the grid, sustainable preservation of your food.
My grandparents talked about keeping vegetables in the root cellar and basement. There were big barrels of sauerkraut down there. They even used it as a place to age meat.
The problem with modern basements is that they're too warm. In the days before the central heating furnace, the basement stayed cold and dark.
To recreate the proper environment, some people dig a cellar as a separate room in the ground apart from the house. This isn't as useful as a cold basement because you would have trouble getting there in bad weather such as ice or deep snow.
Another alternative is to use straw in a barrel sunk into the ground. The barrel or container should be deep enough to go below the frost line or the depth that the ground freezes to in the winter.