Dollar General and their ilk are behemoths compared to the shops that might have served these areas before they rolled in. It's possible they're the only game in town because they engaged in dumping or other dirty/illegal tactics to drive out established businesses.

I'm not an expert on the topic, but I don't think it's a reach to think that they might have engineered this situation.

Or perhaps more likely like a large corporation simply has economies of scale that smaller retailers cannot compete with.

My point is not to explain how they caused it, its to point out that the commenter didn’t even mention the existence of that possibility

It's possible, just unlikely.

The reality is a small business owner does not have the time or wherewithal to negotiate large contracts across hundreds or thousands of brands. They may nail SKU's and quantities better than a Wal-Mart or Dollar General, but at the price of higher costs and lower selection.

You don't really see large scale backlash in communities against these stores for this reason - buying branded at a reasonable price point is foundational for a good quality of life in modern society.

Most people vote with their feet, and are happy with the tradeoff.