A non-driver, I'm in the curious position that some of my nearest supermarkets are inaccessible - no buses. As it is, I have the choice of Dunstable for Aldi, Asda or Sainsbugs, Tring for M&S or Tesco, and Aylesbury for mega-Tesco, Waitrose, all the rest if I don't mind walking. Of course I'm limited to what I can carry, and a faceplant taught me not to try running for a bus when laden with a heavy backpack.

Dunstable Aldi has the advantage that if I only want a few normal household items, I can zip round in twelve minutes flat (the checkout queues look horrendous but they move fast) and catch the same bus on its return journey. All others involve waiting up to two hours for the next.

Online ordering is useful for bulk irresistible offers (like Plymouth Gin at £20 - and I shall check out some of the other suggestions made in this thread), and no doubt will be even more useful in future years should I outlive my mobility, but I shall continue to shop in person while I can.