That "weird kitchen trophy" bit from @rayking is exactly how I saw it before. I used to chuck things like that straight into the trash. Then I saw someone simmer one for broth and actually tried it. The difference it makes is insane, totally changed my approach. Now I bag those things and freeze them for stock. Turns a useless thing into the best soup base you can get.
Yeah the freezer bag thing is key. My buddy wasted so many good bones and peels before he tried it. Now his freezer looks like a science project but his soups are unreal.