It only takes one person, to pick up one extra item whilst out shopping, to clear shelves. Unless you see people filling their trollies with multiple items of the same product, then most people would appear to be shopping normally.
Hoards descending and rampaging through stores is a different matter. It could get worse the longer things go on and I personally think it is unfair of any government to ask the shops to be responsible to police how people shop. If things get too bad, get the Army in to prevent everyone from the worst of it.
Younger generations won't have seen anything like this but it does happen every now and then due to one thing or another.
People have always smiled at me for maintaing an emergency store cupboard, such as a Brexit box. Despite this, I carried on and it will become useful in this emergency.
My mother in law ran her pantry like clockwork and I used to smile at her tactics but they worked and I adopted them to a certain extent. Her motto was this, "have a minimum of two of everything and when you are down to one, replenish stock". She did of course have more than 2 of each item that was regularly used. Her fridge and freezers always operated at capacity and she was a prolific preserver of food.
Her utility cupboards were chock full of jams, marmalades, bottled fruits, ginger beer, fruity drinks etc. She baked biscuits and cakes and at supper time, despite still being a little full from dinner, out they would come and we would all have at least one. She was very adaptable in some ways, her skills were passed onto me but I don't really know if I passed them onto our son.
He would have been aware of how I shopped as he came with us and was given his own little list to fetch items for us. He lived and adapted well to wartime rations for 7 years when we had no choice. He would have seen me bake and preserve but his generation is different to mine, we were different (but not to such a great extent) from our parents.
He is now a parent and getting to grips with his now full term if still small daughter. She is doing well but I doubt we will get to see her in the near future which is a damn shame.
Time will tell how this latest emergency pans out. I would like to hope that we all learn something from it but who knows.