In my experience, it's broken because it's theater. They've already made a top-down decision on wages, layoffs, etc. based on budget, revenue, and sales project

In my experience, it's broken because it's theater. They've already made a top-down decision on wages, layoffs, etc. based on budget, revenue, and sales projections, but they need to pretend that the decision has some rational connection to the value provided by the individual employees, so they impose a process that produces the necessary documents to support that notion. As an IC or low-level manager, there's nothing you can put in the review that will actually change the decision because the purpose of the process isn't to inform the decision, but to justify it. You can't do anything to win or lose a review any more than Hulk Hogan can do anything to win or lose a match; you only lose by failing to put on the expected show.