It is the high cost of living and unions that have in recent decades driven the move of industry to the American South.
But also I suppose that the South has a surfeit of low-skill workers to tap. Let’s not get started on SAT scores, educational levels, innovation rates, etc.
As to welfare levels, NC is the only Southern state with a good record, and 3 of the top 6 states for welfare recipients are in the South: https://worldpopulationreview.com/state-rankings/welfare-recipients-by-state
I happen to live in Virginia, and all of the SSI recipients I know of in this state were born here from parents who were born here from grandparents who were born here...
SSI is basically welfare for people with disabilities that don’t have enough work credits to collect SSDI.
One woman I knew actually got her daughter on SSI too.