No-cook foods generally require no heat but they require a lot of preparation. For example, you cannot simply mix water and macaroni products. The proteins require cooking. There is nothing preventing you from pre-cooking and dehydrating, though…a lot of prep. Beans are very difficult. Again, they require pre-cooking before dehydrating. Lentils, rice, too. Again, the starches are bound up with proteins that need to be chemically changed (by heat or “cooking”) before we can comfortably digest them. Most grains and flour products are about the same. Sure, dried bread (as in stuffing) keeps well, but it has already been cooked. Want to guess what happens with sauces and gravy mixes? The proteins in the gluten get sticky when cooked. Yes, it is perfectly possible to use low temp gel in the sauces, stews, etc. I don’t think the overall texture is the same, though.
Humans in general can eat many things. No, you don’t need to cook anything. But digestion is aided a LOT by the breakdown of various foods beforehand. And, the food requires a lot of chewing in it’s raw state. In some cases, the majority of nutrients are lost, because cooking softens the food. Dehydrating often destroys a lot of nutrients, too. You end up not getting the most out of your food when hiking.
Humans found out that cooking was a big aid to digestion and nutritional value thousands of years ago. While I have tried no-cook on fast pack trips (a single overnight making miles,) I found I missed a hot meal at the end of a long day. It takes the edge off a 24mile day. Breakfast was NOT the same with cold coffee, cocoa was just a lumpy mess, and the oatmeal was simply raw. Not a good start for a comfortable hike.
Back in the early 70’s, I decided that no-cook was not what I wanted to do after several multi day trips with my brother. We had plenty to eat, but, sandwiches, cold coffee on a cold morning, etc made these trips uncomfortable as far as food went. Though a single overnight (or even on a longer trip) once in a while it is fine. My solution was simply to set up a light, versatile cook kit and say the hell with the weight. Stove, Pot/lid, cup, spoon, and windscreen come up to about 10oz, total. Not SUL but well within the “Rule of Ones” for UL travel. (Rule of Ones states everything in your pack for each task must weigh less than 1 pound average. My tarp is a bit over, my quilt is a bit over, my cook kit is a bit less…average is three pounds, for an example. I know, I ignored the fuel canister…)
But, things I can cook gave me a range of foods that is not achievable otherwise. Fritters, stews, soups, rice, macaroni, fried foods, boiled foods, and coffee, cocoa, and oatmeal, cream of wheat, are all tasty treats. Dried spaghetti sauce and spaghetti is a nice change from Mountain House stuff. Even fried garlic/olive oil/red pepper (done in my cup after boiling the spaghetti) makes good aglio et olio. But, you have to have a stove or cooking fire.
That has been my take on foods. There are a lot of good stove-less recipes out there. Try https://pmags.com/going-stoveless-cold-food-for-thought for more.