[thaumasiotes]

> "Indoors" lets you store food without insects or other animals getting to it & stealing it.

This isn't true of human doors; insects are very small.

We've had the technology to keep things in wax-sealed clay jars for quite a while, but I'm not aware that this was done with grain, where preventing spoilage would have been most valuable. Granaries are open to the air. (And devote quite a lot of effort to slowing the spoilage of the grain.)

If you wanted food that wouldn't rot, instead of keeping it in an airtight environment, you dried it.

[bluGill]

Every different food idem needs to be stored differently. There sometimes more than one option that will work, but you cannot treat everything the same.

[IAmBroom]

Dried food requires indoor storage.