He also doesn't have the power to just shut down a part of the government created and funded by an act of congress.

It looks to me like this is the natural outcome of the executive branch deciding what mandates from congress it will uphold. I.E. deciding which laws to focus on enforcing and which one's to have lax/non-existent focus.

Until Congress grows a spine and starts legislating again, the executive will continue to run rampant.

I’m not sure how having Congress “start legislating again” would be effective if the executive branch can simply ignore that legislation under your interpretation.

Congress did this on purpose.

Republican's STATED OBJECTIVE for decades has been obstructionism, entirely so they can go on the news and say "Look how ineffective the government is". Go look at how debates happened on the floor of congress 40 years ago. Go look at the AMOUNT of work done by a functioning congress. Compare it to how little republicans have done in congress since.

Then go ask republican voters and they will tell you that they explicitly prefer a congress that does nothing.

They want a king.