The biggest change in my memory was the evolution from family-run business to chain store. Growing up, there were probably a dozen small markets in my home town. The next level of de-skilling was offsite butchers and scanning registers (our best local store also doesn't have scales, everything is by quantity or is pre-weighed). The next big change might well be no checkout at all.

No doubt, Safeway is going to complain about Amazon drone-delivered groceries like poor Borders bitching about Amazon (after killing off thousands of small bookstores).

Generally, I'd say that the biggest change in grocery stories happened in the 1960's, not now.