I wish people who didn't understand retail supply chains wouldn't post such shitty threads. Have some bloody respect for those trying their best.
People in retail are working in direct contact with hundreds, if not thousands, of people a day. People who have all had contact with plenty of others themselves. They're properly putting themselves on the front line to try and have stock available for you you purchase. They're risking catching Coronavirus themselves, or transmitting it onto their family. They often cannot work from home- it's this job, or no job.
Warehouses can only deliver what stock they have. They also have to split the stock across all of their stores. They only have so many employees (which will decrease now due to more and more of us self isolating), so many lorries, so much time. Deliveries will arrive and be packed as soon as they enter the shop. Again, deliveries can only be packed out by so many employees and it takes a certain level of time to do so.
People working behind the scenes are doing as much as they can to get stock on shelves. It takes time, though. Panic buying is not helping the situation.
I have so much respect for those in retail. Dealing with the customer's who potentially are carrying CV, having to listen to vile complaints and abuse, as well as likely being dragged in for over time. Kudos to them.