When I moved to what I now call the old hometown at the age of 14, there was a nearby regional-chain grocery-- let's call it Fogarty's.
Couple years later they sold out to another regional chain-- let's call it Garamond's-- and the quality slipped just a hair. (By the way, there are still "Fogarty's" stores around the area, but I've never seen another "Garamond's".)
Few years later, they sold the store to yet another still extant chain, call it "IFC".
Then the super evil super Wal-Mart came into town, and the "IFC" folded like a Japanese fan.
And all the people that used to work at "IFC" died in a ditch and the building became a refuge for rats and voles and an infestation of wetas on holiday from New Zealand-- no, wait. Most of the employees got on with Wal-Mart, and the old Fogar-Gara-IFC building reopened--
--as a large Mom-n-Pop specialty, high-end grocery with stuff Wal-Mart doesn't carry. Hired more people, too.
Net effect:
Not one but two decent grocery stores within 3/4 of a mile of each other;
If one doesn't have what you're looking for, the other one will, and a case of microbrew to wash it down;
Just about double-plus-half the number of people at the old store now employed between the two stores.
Your mileage may vary, but my experience is the big stores provide the impetus for the little ones to adapt, improve, or get out of the way of entrepreneurs with new ideas.
