Fishhooks are standard in a PSK, and have many uses other than fishing, such as sewing to repair packs or clothing, stitching up large cuts, making traps and snares, etc.
I agree that their use for fishing in a survival situation is questionable, as it is not likely that you will catch more fish then than you normally do when fishing, maybe fewer. That's why I learned to make fish traps, trot lines, jug fishing rigs, wiers, etc. so if opportunity presents itself I can fish and still have time and hands free to do more productive things. The knowledge may save you when stuff lets you down. Be sure to check local game and fish laws before practicing though as trot lines, fish traps, etc. are illegal in many places.
Some heavy weight, say 35- to 50-lb., braided fishing line is very good for tying out tarp shelters, lashing support poles, making traps, setting trot lines, and so on. It's much lighter and more compact than paracord, too, for a small EDC pouch like you have.