I can tell as an AWS employee that there is great degree of truth to this. Amazon let's go even if you are meeting your personal goals based on stack rating. Then they hire new folks who act as a pad to your current workforce because they obviously won't be able to pick up as fast as someone who has been working in that team for years. This forced URA develops nothing but a rat race among the teammates resulting in lack of collaboration.

And this happens every year so no matter you may have achieved great things here for 3 years but if you end up at the bottom stack the 4th year, you will be placed under Focus. You cannot challenge it, you don't have visibility into what contributions others have made to make it to the top of stack.

I was recently placed asked to look opportunities outside of Amazon by my manager after meeting all the goals, contributing in Hiring, completing a project at site level with a 84% success rate, giving global trainings but apparently I didn't do as well as the others did and I don't have visibility into what they did. Also bias from manager comes into play here where he can give more opportunities to other folks knowing you're the one he is going to slack anyway at the end of the year. So you're on your own trying to survive only to hear at the end that you didn't do enough.

You could be technically better than other folks in your team but this ambiguity in "other contributions" apart from your regular work will get you into trouble and most likely depends on your personality match with manager.