There was no competition in many places dollar stores operate. They moved into those places specifically because they were underserved by larger retailers.
Ehh I disagree. "No competition" yet I bet every home in the area still had groceries in the kitchen before the dollar general opened.
I agree, at least in my area.
Two neighboring dollar stores just went out of business in a town I commute through. The culprit? A new Harp's grocery store a block away.