Let me share details on how QuickBooks handles your product/service reports, generalmedical.

The Sales by Product/Service Summary report will tell you how many of each item or service you have sold, the total dollar sales, and the profitability of each product or service. This is the reason why the value of your invoices shows in the quantity column.

The sales reports in QuickBooks will provide you helpful insights into the things you buy and sell, as well as the status of your inventory. To learn more about what reports you can pull up to know your best sellers, what's in stock, and still on order, you can check out this article: See your Sales and Inventory Status.
 
Please let me know if you have other concerns about managing or running reports in QuickBooks Online. I'm just around to help you out.