OK.
– Panic buying (everyone trying to buy stuff in the same few weeks) = bad. Leads to shortages.
– Stockpiling (slowly over months) = good. Shops can get in more goods to replace what's sold. Stockpiling in homes increases the overall amount of food stored in the country.
– "I can't afford to stockpile." Fair enough. Other people stockpiling will take the pressure off the shops during the crunch period, which means there will be more left for you.
– "I eat fresh stuff and I can't stockpile that anyway." Correct. And if there are hold-ups at Dover/Heathrow/anywhere, you won't be getting that fresh stuff... SO YOU'LL BE EATING SOMETHING ELSE. Do you have the Something Else in your house, or will you be going out to the shops for it like your eleventy billion neighbours the same day?
– "I don't eat stuff that comes through Dover." Sure. But see above. All the people who do, will turn to replacement foods and start buying the stuff you want.
– "The disruption won't last for long." How many days are you prepared to eat half-rations or less? Don't forget that supermarket supplies will take at least as long to build up again as they took to run out. So if you have your usual three days' worth of food in the fridge and live comfortably during the actual transition, when you go out to the shops on Day 4, they won't have restocked yet. And when they do, they'll be descended on by all the other people who had three days' worth of food too. So all you've done is delay your personal shortage by three days.
– "The UK should plant more X". (I've genuinely seen this one on MN). It's January. Deadline's March. You're a fuckwit not being helpful.