Not that it's a seriously likely thing to happen, more a reflection of how spoilt we are by the 24/7 disposable consumer-goods culture, even in relatively hard economic times. Reading up on the WWII home front experience & all the fantastic ways people (women) then coped with shortages of basics, I can't imagine being asked to present a ration book at Sainsbury in exchange for my one solitary egg for the week. They'd have to barbed-wire the shelves and post armed guards... What would happen to all those fussy kids? Would they just starve to death? And I'm not sure I could knit a sock to save my life.
AIBU to think that, unlike our grannies, too many of us are a bunch of trembly-lipped 'ruined my life by delivering the wrong sort of tomato' wussies that would cave at the first mention of 'make do and mend'? ... or are we just as tough and capable of knuckling down in a crisis?