Somewhere back in the dark ages there was some agreement between the executive branch and Congress on Congressionally required reports. I forget whether it was USDA and the Ag committees, or the President and Congress.
This Project on Government Oversight post
describes a bill in Congress to put all such reports online.
I'd love to see a study of these reports. I suspect in many cases they are a sop thrown to assuage someone's pet concerns. A Congressperson has a bee in their bonnet, or some interest group is pestering them, so instead of enacting some legislation everyone agrees on requiring the bureaucracy to submit a report. By the time the report is completed and submitted, the bee is dead, the pesterers are disbanded or moved to something else, so the report gathers dust, unread, but having served its function in the great and glorious American political system. The only cost was the waste of a bureaucrat's time, and we all know that's not important.
Sometimes, and more perniciously, the requirement is for a periodic report. I say more perniciously because it eats up time every year. At least it does if the bureaucrats honor the requirement. That doesn't always happen, because like kids suspecting a "beware the dog" sign is a bluff, bureaucrats may decide to do their business, guessing Congress will never notice the omitted report.
Some Congressionally-required reports are worthwhile--like the State Department's reports on terrorist states but I doubt the need for most.