Agreed. How much cooking oil do think get dumped down drains and into landfills all across America--from the home to restaurant use?
Home use no doubt gets dumped. As for commercial use, the cooking oil gets recycled. There are companies that pay for the old oil. We owned a bar in Northern Wisconsin, and the rendering plant simply gave us a barrel. We would pour the used oil into the barrel, the company would come by with a new barrel and take the old away and mail us a check.
I know it also gets used for cattle feed as well.