Manufacturing and agriculture create wealth also. Importing and retailing, not so much,
Those who serve the market create wealth. The Division of Labor creates wealth all along the way. In fact, every new division in the labor change creates wealth because it makes the market more efficient.
You really believe that retailing creates no value? Of course it does since a wholesaler with a warehouse full of a commodity sells it to a specialist, the retailer, who sells it for far more than if he tried to own his own. The difference between what the wholesaler could sell and the sale of the retailer.