(Source: courtesy of Google)
As part of a group, you are able to give and receive support, and encourage each other.
Within a group, the individuals are more than likely from different backgrounds and so each member brings different skills with them. This benefits the group as a whole.
The final output should be far greater in a group, because more ideas and views are present.
Personally from my experience, I found it hard to try to organize people when you are not talking to them face-to-face.
Some people, who do not participate, leave the others to do all of the work, which is not fair.
If the whole group has not contributed to the discussion then it can feel as if it was a waste of time.