Earlier quoted context omitted.
Those are really not alternatives to the mentioned uses. The freeze dried food selection is somewhat limited, tends to be very salty, takes substantially more time to prepare, and generates a lot of waste you get to continue hauling around. If your goals include speed or (less) weight, those freeze dried options are really far from ideal. To get around the weight issue you mostly need to plan and package your food yo…
The things i'm talking about are a single pouch per meal. There's no more or less waste than mixing up a sack of goo. Many can be eaten dry in a pinch. Have fun eating dry soylent. I can't really speak to the exact sodium content, but it's more than reasonable for emergency rations or hiking or SAR. You're not eating this stuff every meal for the rest of your life, and if you are, you deserve what you get.
It also gives you a lot more control over portions, which can be an issue as well. There is no point packing more than you are going to eat.
I brought up the salt content not for health reasons, but taste. Many of the ones I've tried have been so salty I've had trouble finishing them even after a day of backpacking.