[AnthonyMouse]

> In this hypothetical, communities would see the same effects as if Walmart chose not to exit. They would just shop and work at "Not-Walmart", same as the old Walmart.

Not-Walmart is a different company that doesn't have a union, and if they should get one, actual Walmart can start selling goods to some different Not-Walmart who doesn't. Then Not-Walmart #2 drives Not-Walmart #1 out of business by offering lower prices if the union manages to increase Not-Walmart #1's labor costs.

After people have seen this happen they realize the union can't actually secure them more than the wages available in the free market without causing them to lose their jobs, so when they take a job at Not-Walmart #2 they wonder why they would want to spend time organizing another union and paying dues.

> Some might argue prices might increase due to an additional corporate layer, but then the question I would have is why wouldn't Walmart just raise the prices themselves and take those extra available profits for themselves?

These kinds of operations often have minimal overhead. Existing Walmart pays a salary to a store manager. Not-Walmart is owned by the person who would have been the store manager and makes "profit" equal to what Walmart would have had to pay in salary.