Oh come on. Near trebling, which is what has been seen for some products, is not a ‘modest jump’.
Whilst there would always be things which couldn't be planned for having a bit more stock in each shop, and also within wearhousing, would clearly have eased the obvious empty shelves and therefore reduced the amount of panic buying.
Locally to my there's a village (probably a town but the locals like to think of it as a village still) where the local supermarket was too small for when it was built in the 1990's, since then there's been about 500 homes built, even a decade ago someone expected it as a rubbish supermarket but a brilliant corner shop (think a step up from an express but not by very much). There's been planning granted for a second supermarket (2.5 times the size, and no it's that not large it's just the other is so small) to be built, yet it hasn't been built yet.
However if it had been built then:
There would have been a lot more stock
There would have been more delivery slots (the new one would have done deliver whilst the current one doesn't as it's too small)
The pressure on other supermarkets in nearby settlements would have been reduced
All in all it would have been quite a lot better, but because there's no slack designed into the systems things haven't gone as well as they could have done.
It's not that it would have done badly under normal circumstances either as the settlement has a population of 9,000 and has a number of smaller settlements around and about which don't have much more than express type stores.