Why do people unite in groups. What does a group give to a person?

In ancient times, people united in groups to protect themselves. It was difficult to survive alone, since danger was waiting literally at every step. Wild beasts, natural disasters and so on. Now people unite in groups mainly because of interests, although there are also cases of uniting in a group for survival. Common interests are what bind people together. They unite in groups, companies to be closer to like-minded people. This is the main purpose of any social group – to find like-minded people. In this case, the type of activity of the group can be absolutely anything.