I would rather eat a trout than a tooth rotting sugar filled snickers for the possible aftermath of not being able to eat again!
Actually getting fish is hard enough for most people even with a dedicated tackle box, with just a hook and line that's typical in survival kits it's approaching impossible.
It's just one of those staple things in survival kit that nobody uses, but still want it to be there.
I have not been fishing since high school, but I often fished with nothing more than a cane pole, some line, hook, sinker, bobber, and a worm. I don't think you need anything elaborate to catch fish. But maybe the fish have gotten smarter in the intervening 30+ years.
Ironically, last night a shooting buddy and I were talking about fishing. Neither of us has done much in the way of fishing in a long while and we both were remembering the fun it was to fish with a cane pole and very limited tackle.
I do tend to think that a fishing kit is extraneous to a limited survival kit, although the line could be quite handy for many things, as might the other items in the "fishing" kit.
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Warning - I am not an expert on anything having to do with this forum, but that won't stop me from saying what I think.

Bob