There are scores of grocery chains in the US, not 5. There are thousands of independent grocery stores. And literally hundreds of salt options, even at Kroger.
Seriously. Even the most basic supermarkets stock like at least 10 different kinds of salt. Iodized, non, kosher, sea, for grinding, packets, in disposable shakers, etc., and often a couple brands, e.g. Morton and Diamond. And a larger supermarket will have pink salt (Himalayan), various fancy sea salts, fleur de sel, flavored salts...
https://en.wikipedia.org/wiki/List_of_supermarket_chains_in_...
https://www.kroger.com/search?query=salt&searchType=default_...