this is the biggest benefit of 1:1's in my opinion.

Often, individuals can claim credit simply by being first and loudest. For example, and individual can highlight a problem area that someone is already working on in the team and loudly talk about the flaws in the current approach and how they will solve it. The individual need not actually solve the task if the first person finishes - but now the success is subconsciously attributed to the thought leadership/approach of the new individual.

Good managers/leadership teams have mechanisms to limit this type of strategy, but it requires them to talk to everyone on the team - listen for unsaid feedback and look at hard artifacts. Otherwise you quickly have a team of people who are great at nothing more than talking about problems and dreaming of solutions.