Why did Epicureans value friendship?

In the context of the history of ethics, Epicureans valued friendship primarily as a means of achieving security and happiness, which were central to their philosophy of life.12

While friendship initially stems from [utility]—as every individual, being alone, requires the support of others—Epicurus taught that once established, it becomes desirable in itself. This transformation allows utility to be "surmounted" and sublimated into a form of love. For the Epicurean, friendship serves as a vital protection against the "noise of the world" and human competition, providing a sense of safety that allows one to "live hidden" and maintain a quiet, happy life.12

The importance of this bond was so profound that Epicurus argued a wise person would suffer for a friend as if they were experiencing the pain themselves and, if necessary, would even die for them. Ultimately, friendship was considered the "law" of the Epicurean "garden," representing one of the purest joys of human existence and a necessary component for a life free from pain and mental trouble.213