There is arguably no way to judge "fairness". Employee A gets assigned to work on LLMs. Employee B gets assigned to work on Android 9/Mac OS 12 security patches. Another example includes unforeseen difficulties. I have a friend that signed up to implement a feature. That feature would have taken 1-2 weeks in any standalone app, but, he happened to be on web browser team and the number of edge cases that came up and the amount of back and forth between standards committees meant it ended up taking 2 years. He was judged poorly even though all of it was out of his control because everyone though it should have taking 1-2 weeks.

I feel like I'd prefer some balance. There are superstars. We know them. We can easily point them out in peer reviews. But, we're also a team, there's lots to do, not everyone gets to work on the high profile easy to identify "impact" parts.