Really? And how long will your stash last? Most food these days won't last you the few years minimum you will need.
So your argument is that since we can't be ready for everything, therefore we should prepare for nothing?
Like I said, my primary concern is a major earthquake. That would probably disrupt supplies for only a few weeks. A major disease pandemic, like a "super-flu", might last longer, but no more than a few months. A major global crop failure cause by a volcano or asteroid, would be a bigger problem, but humanity has survived these several times in the past. The worst was probably the famine of 1315-1317, which may have killed 25% of Europe's population. But back then Europe relied on crops, such as wheat, that needed warmth, sunshine, and dry weather to harvest. Today, we have crops, such as potatoes, that can thrive in cold, wet, and hazy conditions. Supposedly people survived that famine by going into the woods and digging up earthworms to eat. Those people were your ancestors. You probably wouldn't be here if they had the same attitude towards survival that you do.