22lr does have a few good points, cheap, lite, accurate, small, and not very loud.
But it has some drawbacks too. Wont go through anything, May take more than one shot to drop attackers or big game, no long range capability. And the latter are 3 things that I want in a shtf weapon. Now a small, preferably folding stock, 22lr of some sort would be a great gun to keep in your pack, for hunting small game. Shooting small, furry or feathered game with a .308 or 7.62 would end up very nasty and probably not very useful.