The benefit in terms of survival
If mankind spends around 20% of is awake time communicating with others and giving information at loss, it is doubtless because he takes a crucial advantage of it. She must counterbalance the inconvenience of sometimes doing things in the group's interest but to his own detriment.
Human being has little chances to survive on his own. But L'être humain a peu de chances de survivre seul. But unlike other animals, he forms less alliances with others outside his own family. He might then have developed a capacity of elaborate language in order to give information and thus showing that he can be accepted by the group.
Chimps can only unite when two or three (not to be confused with a pack or a herd: in a coalition, individuals have chosen each other). Probably thanks to language, mankind is able to form alliances with several persons. In a small group, choosing individual strength brings more to the whole ; in a large group, strength is brought with the number of members and thus enables the ability to cooperate together.