They are like the police or the car salesmen: they do this every day or so, you do it once every 5 years. If you're not careful, you won't even know what happened there, not until you see the consequences. Protect your own career and interests.

The best thing one can do both for oneself and the remaining employees is vote with their feet. If enough employees do that, things may change. Don't burn bridges when you leave.

I work for a boss whose anonymous yearly reviews are atrocious every single year. Nothing ever changes, he's still running the department. The organization is rotten to the top, and no honest feedback will ever change that. I bet not even most of us leaving.