> Could you give us an example of a specific FAA or NTSB regulation which has a suboptimal benefit:burden ratio?

Sure. The air traffic control system is 20th century technology that has air traffic controllers doing things manually that could be done by computers. A better automated system would have the same or better safety while requiring significantly less labor.

The FAA has been actively working to modernise the air traffic control system for decades. It's a hard problem. I fail to see how that addresses the point?

The point is that it's a hard problem whose solution yields large returns, but we're expending resources to solve it at a rate that takes decades to produce the solution.