How many companies actually do annual reviews and log the goals/achievements into an internal system? I just asked my software engineer friend at Google and apparently it's not a thing for them.

I talked with a mentor at my firm and apparently annual reviews don't even impact next year's total comp! It's all for me to "grow my career". But can't I just write it down on my own spreadsheet to keep track? I just feel bad for my manager because he's in charge of so many people and this process takes so much of his time and I think there are different ways for him to know what his employees are up to! (And I feel like I'm selling myself a little too much whenever I write these self-assessments.)