Walmart has taken apart regional grocers for forty years.
Winn-Dixie shrank. A&P vanished. Dozens of good local chains sold for parts.
Texas did not follow the script.
In the state where the supercenter model is strongest, a private San Antonio grocer kept growing right through it. The usual explanation is that Texans love the place. That is a feeling, not a mechanism.
Mechanisms leave evidence behind in the federal data. Feelings do not.
The short answer is that Texas grew faster than Walmart could absorb, and the stores here are physically larger than almost anywhere else in the country.
Both of those are federal statistics, not folklore.
The real subject starts there.