B. -
Items like cereal, crackers, etc. we store in it's packaging. Most often, there is a bag inside a box, & the bag can be folded over & the box closed.
However, most baking goods, such as sugar, flour, powdered sugar, etc. come in a single-layer packaging.
As a result, this can become enticing to unwanted guests, such as mice & moths. They are harder to seal, & easier to access. Additionally, once there is a single small hole in the packaging, it is a mess in your pantry.
For that reason, many people store baking supplies in cannisters. This goes back generations.
More recently, I think, people got on the "if some is good, more is better" & began storing -everything- in a container. Cereal, pastas, rice, crackers, cookies... you name it. If a business could make a container for it, they would, & people would buy it, boosting the economy.
Realistically, if you use your food within a reasonable time, you are correct, it won't go stale. There is no health risk as long as there are no mice or bugs getting into your food.
Personally, I have three cannisters for baking goods (flour, sugar, powdered sugar). We also got a set of see-through acrylic canisters for items like pasta, rice & beans, but we are "lazy" & just keep the items in their original bag, & then pop the bag into the canister! The purpose is more to keep the bags organized, rather than in a haphazard pile on the shelf.
In any event, as long as your kitchen is clean, you use your food & keep your cupboards tidy, it sounds like you have a good system for what works in your family!!
T. =-)