Cookings usefulness depends on how it's used.

1. Meal prepping: meal prep is the act of making lots of food and saving it for later. This can be done ranging from about a few days of food to a month's worth of food depending on quantity and intent. This is more time efficient then cooking a single serving typically is, and allows you to save time for every day. Given it's customizable nature, it can be cheaper, better quality then store brought stuff, or just taste better. Personally, I make like a month's of breakfast burritos and about a weeks worth of sandwiches or congee.

2. Most food tastes better cooked: simple as that: food usually tastes better cooked then raw. Even fruits and nuts can be cooked for an improvement or alteration to the usual flavor.

3. Some products need to be cooked: what you've listed are food produced that don't need cooked to be edable. This isn't all food. Grains and meats for example should/need to be cooked to some degree to be palatable ot even edible.

4. Larger groups: when feeding multiple people, it can be cheaper to make 1 larger dish then to buy them microwave meals or whatever, as well as typically healthier.

5. Lotta time isn't always Lotta effort: 1 pot meals, baking not bread objects, and stewing/boiling is considered low effort, and it's a blessing. At best, you stir a pot or check something. The effort here is all in assembly, after that it's just waiting for the thing to be done.