I would ask why is there a set cycle for raises? If an employee is valuable enough for a raise why wait and risk a competitor poaching them before the cycle comes around?

That may sound far fetched but my current company has a very rigid and well known cycle and I swear that recruiters know about it. I get way more recruiter calls leading up to raises than afterwards.

Good on you for noticing that the annual review data is artificial. I suspect that is why these processes exist. Companies want to base there decisions on data and don't care if that data is meaningless.