Macaroni products keep for a long time on an unrefrigerated shelf.
Flour does not keep as long because it has more problem with tiny bugs getting in it... or hatching and growing in it.

But, if you want space savings, as much food density as possible
spaghetti standing upright in a 5 gallon bucket is like pure, solid macaroni product.
(as opposed to elbows, which a 5 gallon bucket would be mostly air.)

Wheat berries last longer than either of these.