Since the hoarding topic came up quite often here (at least in small talk), i would like to offer a sane explanation that does not involve stupid selfish fellows as the root cause of things missing in the supermarket.

A well known fact is that people usually spend 1/4 to 1/3 of their time at workplace where they use the sanitary.
During lockdown people s**t at home and even a 1/5 or 1/6 increase of demand in toilet paper made it disappear from the shelfs since it is the single largest item in stores and had a very sophisticated size to demand ratio to not cost too much storage space compared to the low cost/big size.
Granted, at some point when it got obvious there will be a shortage in supply, some people overreacted, but those where not the root cause but a symptom of temporary shortage.

An estimated 40% of meals had been consumed either in restaurants or at workplace offerings.
People still continue to eat for some reason but now have to cook for themselves and get much more stuff per person from supermarkets etc.

Since what you see in shelves is only a small part of "food logistics", i would like to remind that most of our food is on the road in "Just-in-time" Trucks always filled to the brim.
It is just not possible to suddenly have more items in store from one week to the other since there is no additional capacity available to deliver it.

So from my estimate, the missing products where either the most popular (everyone can cook noodles, right) or those with the longest time to replace like flour and yeast. Those have long shelf life and are usually not requested that often.
Now everyone is at home doing cakes

And yes, the few idiots with carts filled up with a late giant prepper assortments exist.
But real preppers did help the system because they never had to go out for TP or noodles since even government advice is to have them in stock for 2-4 weeks supply...

Sorry for the long post, but i got especially triggert by my local mayor stating "If anything is missing in the supermarket, it is due to someone having bought more than he/she needed"
Nooo, it is a systematic effect that no buyer or supplier has a fault in, but politicians not understanding they are not steering a speed boat but a literal oil tank(er).