There can be small grocers in big cities and faceless corporations in small towns, in fact in my experience in midwest America small towns (sub 5000, say) have 0 shops, people drive the 15 minutes to the nearest walmart
midsize cities / college towns ~100k will have a specialty butcher and a tobacconist where you can actually get to know the shopowners
I'd generally agree with the stuff about everybody just driving to Walmart, but that was just to stock up on nonperishables/freezeables. There was always the local mini mart/gas station, movie store, school, church, pool hall, bar, etc. And everybody tends to know everybody anyhow, because you often have inter-family relations dating back generations.
midsize cities / college towns ~100k will have a specialty butcher and a tobacconist where you can actually get to know the shopowners