I'd point to the graphs (and the various dots below them - there are lots of graphs there).
The lack of accountability is a reaction to this (trying to protect the members / lobbyists who helped draft it) with the addition of the current polarization of the various parties in state and federal legislatures.
From the Congressional Research Service ( https://en.wikipedia.org/wiki/Congressional_Research_Service ):
* The Legislative Reorganization Act of 1970 and other 1970s Sunshine Reforms - https://www.congressionalresearch.org/LRA.html
I'd point to the graphs (and the various dots below them - there are lots of graphs there).
The lack of accountability is a reaction to this (trying to protect the members / lobbyists who helped draft it) with the addition of the current polarization of the various parties in state and federal legislatures.