Another simple explanation for the decline might be economies of scale or economies of scope (or both) . Thirty years ago they might have had a smaller effect o

Another simple explanation for the decline might be economies of scale or economies of scope (or both) . Thirty years ago they might have had a smaller effect on small businesses (like coffee shops and retailers), whereas nowadays complex logistics (economies of scale, ie. walmart) or versatile production facilities (economies of scope, ie. starbucks) have a bigger influence on profits.