If you're in a field with fierce competition the ones who focus on credit/recognition/awards get some sort of boost above their actual potential. Meanwhile those who don't will get punished and the ones who end up doing well despite it just had better natural aptitude on top of having more pleasant characteristics. It's some sort of Berkson’s paradox.

Yes, they are better colleagues. They do not get promotions, pay raise or any other recognition or reward from management. Even from colleagues who hold them in high regards, they do not get praise on meetings as much either.

However, people with ego end up being praised more, in front of bosses or others, because people want to be on their good side. And that makes them look better, they end up promoted and seen as higher performers.