Actually it's not universally true that people working closely together know who is competent and who is not. Because you yourself need to be competent to know if others are doing a good job or not. If you are surrounded by incompetent morons you as likely might be labeled as incompetent by them and since they are the majority you lose the battle. It doesn't even have to be done on purpose by the morons, they just don't know they are bad at what they are are doing and create a kind of a circlejerk re-assuring themselves