It is mostly handwringing about unrealistic scenarios as these types generally assume that all militaries, emergency response groups, every book, factory, and s

It is mostly handwringing about unrealistic scenarios as these types generally assume that all militaries, emergency response groups, every book, factory, and source of expertise completely disappears and it's up to you, the lone hacker on a farm or something to become the source of expertise through a squirrel-cache of carefully curated information. That's very unlikely to happen simultaneously for every single country and if it does it's probably an extinction event.