My personal (recent) experience, from yesterday's shopping expedition.
Aldi and Woolworths almost devoid of red meat, chicken, frozen goods and toilet paper. Some other not so important items missing from shelves or in short supply. All in all though, no danger of starving to death. I suspect if we had gone to Coles the story would have been similar.
As you exit Woolworths after checking out, you encounter a butchery. The normal quantities of every cut and variety of meat were on display. In our local independently owned Fruit and Vegetable shop that also sells milk, dairy and deli products, meat and many grocery lines, newspapers, magazines, flowers, and much more there was no evidence that anything was in short supply. In fact they have a sign outside: "Fresh deliveries daily, no need to panic buy". I suspect if we had ventured into our local independently owned Foodworks store the story would have been similar.
In pondering the alleged "Supply Chain Issues" it seems clear to me that there is no problem with supply, but it lies with the chain. If stores are willing to source produce from any available source, there is no problem, but when they have a rigid policy for sourcing produce through a strict supply chain, it can easily be disrupted.
I recall one day well before the COVID-19 pandemic when we were away from home one day we went to a fish and chip shop to get some fish and chips for lunch. The lovely young lady behind the counter apologised for them having run out of chips. I responded: "There is a supermarket next door, go buy a packet of frozen chips and cook them then." The response was: "Oh, no I'm not allowed to do that!" So we ate fish and potato scallops. At the end of the day, they are there to supply customers with fish and chips (as well as other items). It shouldn't matter to them how they achieve that end (as long as it is legal and not life threatening).
Another example from well before the COVID-19 pandemic: On my way home one day I thought to myself: "I could go a burger for lunch today." Thus, I called in to Hungry Jacks (the burgers are better there, apparently). I noted an unusually long queue that didn't seem to be moving, except as people gave up and walked out. After a while, without saying a word to the customers, a young female staff member walked to the counter and affixed an A4 sheet of paper to the counter that read: "Sorry, we can't make any burgers, we have run out of buns." Again, making and selling burgers is a major part of their business. They should have ensured that they had plenty of buns. About a block away is one of their major competitors (McSomething). I personally know one of the managers there, and I know that they regularly throw out cartons of buns that have not been used by their use by date. I guess you can't cooperate with your competitors to ensure continuity of business...
"They" have it all wrong...