//but once inside it was impossible to social distance as the aisles were so narrow.//
Exactly. Even in larger stores the idea that everybody can keep two metres apart is pure fantasy. You head down an aisle, get to the end and passing from behind a row of shelves, out of your sight, comes another customer. You're within a foot or two of each other before either of you knows it. You can keep apart in the queue to get in and you might be able to keep apart in the queue to get out - provided the queue is not alongside a row of shelves laden with goods - which it usually is and then you get shoppers infiltrating the two metre gaps to pick up their goods.
Total farce, window dressing and, judging by the continued rise in the number of new cases, of no value whatsoever. (Cue: "Ah, but without it the numbers would be even greater").