Small businesses are a pillar of capitalism and of a healthy economy. They provide a path into the middle and upper-middle class for people who don't have elite connections or a fancy college degree. And they distribute capital income broadly, so that the gains from business ownership aren't concentrated among a few wealthy shareholders.

Retail is a big component of small business. In recent decades, big chains have pushed out mom-and-pop stores. But there has been hope that e-commerce would provide a lifeline for small retailers.

There's just one problem. E-commerce in the United States is increasingly dominated by a single platform — Inc. As of 2018, the e-commerce giant had grabbed about half of the online retail market.