Dealing with specific issues may cause isolation, and a feeling that you are alone in facing your problems
Group counseling can help you to counteract isolation by assembling people with similar issues to enforce that difficulties are not specific to one person.
Group counseling is a form of therapy, which can be beneficial from shared experiences. Usually, it's focused on a particular issue, like obsessive-compulsive disorder, anger management, bereavement etc. While a therapist usually manages the group, contributions from other members are considered valuable since all in the group share similar issues.