Isn't the point of the article that the Shopify Fulfillment Network will be available to all merchants (that pay for it)?

Most of the Shopify plugins exist to give a store owner an advantage in sales, conversion or marketing. Sure execution counts, external branding counts, but Shopify is a closed platform. You use their plugins and approved apps. And most store owners rely on these plugins to some degree, to help them build brand awareness etc.

Eg: https://apps.shopify.com/browse/sales-and-conversion-optimiz...

Shopify levels the playing field which is great. But if everyone selling Bananas is on the same field, using the same plugins, switching fields could be a great way to differentiate and possibly optimize beyond what Shopify can help you with.