It seems to me that the supermarkets have caused a lot of the problem themselves. When people started stockpiling, they reduced their opening hours drastically, ostensibly to give them more time to stack their shelves.
Now it has been reported that stockpiling has stopped to a large degree as shoppers have realised that stocks are available. If the supermarkets returned to their normal opening hours therefore, shoppers would go back to their normal pattern of shopping and the horrendous queues to get in would disappear. Social distancing would still need to be followed but people could have more confidence in finding a quieter shopping time.
The online and click and collect availability has been rarer than hen's teeth and there must be many people lucky enough to have managed to get one but who do not really need one. The over 70s with health issues should be first inline for them but despite obeying the instruction to stay at home, they (and I include myself and DH) have no option but to brave the queues to shop once a week.
Last Wednesday we went to the hour set aside for over 70s and vulnerable, at our Tesco Extra, only to find two huge queues snaking round the car park with all sorts of ages there and no-one organising it. No notices saying what we should do so we gave up and left. We shall need to try again in the coming week and the thought fills me with dread but I now have quite a list of stuff we need so it will have to be done. I wish I knew when the quieter times would be. I'd go in the middle of the night if only they would revert to 24-hour opening!