When I run financial reports, I choose the drop down option at the top to show only non-zero rows, otherwise the report is unnecessarily long. Maybe that helps?
I ran "sales by customer summary" (instead of by product/service) and it allows me to turn on or off those unwanted details. Seems like both reports should have...
That report has too much info that can't be removed/customized in QBO, like % of sales, qty, avg price. What if you just need to simple total by month?