Here's a perfect case in point that relates to the work I do:
The USDOT sets rules and standards for geometric design, highway signs, and pavement markings on the National Highway System. They do this under authority that has been vested in the agency by Congress. Do we really want 535 elected officials -- most of whom don't know the first thing about roadway design, motor vehicle safety, etc. -- dealing with this kind of minutiae through legislation? I can see this argument from both sides.
I have long advocated a kind of "compromise" approach that lets competent professionals work in areas where their expertise is needed while at the same having Congress meet its constitutional duties to legislate these matters: Simply have Congress assign the responsibilities for developing policies and guidelines to an Executive Branch agency (like the example I cited above), but make sure Congress actually passes a statute that makes the policies and guidelines a matter of Federal law, not an Executive Branch regulation.
A good additional consideration here would be for Congress to include a sunset provision in every such law that forces it to revisit every one of them periodically. In the case of highway signs, for example, Congress can pass a statute that says: "The USDOT's Manual on Uniform Traffic Control Devices will serve as the design standard for signs and pavement markings on the National Highway System for a five-year period that begins on January 1, 2019 and ends on December 31, 2023."
Does this sound reasonable?
Yes. That makes the elected representatives fully responsible for whatever they approve, in a way they can’t evade.
Mark