This is probably primarily because there's been many decades of work by governments and private companies on the packaging and design of these meals to make the

This is probably primarily because there's been many decades of work by governments and private companies on the packaging and design of these meals to make them lighter, less hassle, more practical, etc. If you watch an unboxing of a modern meal from some of the YouTube channels linked, they're actually impressively compact, easy to deal with, and thoughtfully engineered. (Even examples from some developing nations seem pretty respectable. A lot of countries even put contact information on the packaging to solicit user comments!) Much of the food is put into small bags, meant to be thrown in a pocket or pouch to snack on later. It's even common in Europe to just put snack foods in pretty standard branded packets, which is a well-tested solution. Military personnel tend to cheerfully gripe about anything that was annoying about their service—it's an almost universal bonding thing across cultures. When it comes to packaged meals, the griping seems to focus on 1) how it tastes and 2) whether it gave them digestive problems. I think, admittedly as a layman on military packaged food, that the state of the art of packaging design/engineering is pretty solid.