The performance review cycle nobody defends
Ask five people why the annual review exists and you will get five answers.

Annual reviews are unpopular with everyone involved, and the reason is that they are trying to do four incompatible things in one conversation.
The four jobs
Feedback on how someone is doing. Calibration of relative contribution. Pay and promotion decisions. Development planning for the year ahead.
Combine them and the money crowds out everything else. Nobody hears a development conversation while waiting to find out what their raise is. The manager, meanwhile, is writing a document for a committee rather than talking to a person.
Feedback should not wait for a cycle
If something in the review is a surprise, the manager has failed at their actual job. The cycle should be a summary of conversations already had. Anything genuinely new belongs in a conversation this week.
Calibration is where fairness lives
The moment ratings affect money, you need cross manager calibration, because generous and harsh managers otherwise create real pay differences for identical work. Keep calibration focused on evidence and scope, and watch the patterns: which groups cluster low, whose achievements get described in terms of personality rather than results, who was on parental leave and got quietly downgraded for it.
Development plans need a budget and a date
Most development plans fail because they name an aspiration with no owner. A plan that says stretch assignment leading the migration project, starting April, with the manager as sponsor, is real. One that says improve strategic thinking is not.
Simplify the paperwork aggressively
Every field in the form is a tax on every manager. If a question does not change a decision, delete it. A good cycle can run on four questions and half a page. Most companies are running something closer to seven pages and getting worse information for it.