I'll just say this... In a lot of instances annual review (or any long cycle review) serve a very important bureaucratic purpose for employees: getting raises

I'll just say this... In a lot of instances annual review (or any long cycle review) serve a very important bureaucratic purpose for employees: getting raises (and/or promotions). Nearly everything else in a performance review should be handled in some other way, but it's hard to push management into the position to reward an employee financially outside of such a formal setting. This comes with the disclaimer that if your company sees value in performance reviews (and therefore chooses to have them) than it probably also is the type of company where getting a raise outside of a formal setting is hard.