“Why do we even continue to put up with this from our government agencies. It’s truly a puzzle.”
The short answer is, “Because the agencies can get away with it.” Congress has abdicated its power and allowed the Executive to become much more powerful than it was supposed to be under the Constitution. Yes, write your Representative and tell them to put their big … uh, person, pants on and do what the framers of the Constitution intended: represent the people and properly oversee what the Executive is doing.
Many years ago my father, a retired Naval Aviator and then active GA pilot, was a member of the US House of Representatives. During that time he was on an official visit to Israel, a function of being a member of the House Armed Services Committee. While there he was invited to fly a training hop with the Israeli Air Force in the then-new Kafir fighter. He accepted. (Wouldn’t you?) One of the interesting things is that, at the time (late 1970s) all Israeli training hops flew with full live munitions just in case someone wanted a repeat of the 1973 war. He was asked if he was willing to engage in combat should the need arise. He readily agreed. The State Department, a function of the Executive Branch, had apoplexy and forbade him from flying the hop. He pointed out the separation of powers clause in the Constitution and explained to the US Ambassador that the Executive branch had no power over the Legislative branch. He flew the hop. For the rest of his life the picture of him sitting in the Kafir with his Israeli IP resided on the wall of his office.
So, yes, the Congress can tell the Executive what to do, or to go pound sand for that matter, as the case requires. Time to get them to do their jobs.