For the beginer, or whom wants to improve their skill: to learn from other's better works, to listen to other's suggestion or comments about his/her works, in order to know how to make yourself better.
For middle range: through the discussion and comparing, find out what is better, where to improve, get some good idea or so. Also, to make things more clear on those confusion points.
For Aces: to share the experience, thought, good works, to help people improve their skill or mind set in a short and stright way in order to avoid unnecessary waste about their energy and time.
It's totally meaningless to compare who is taller or not, as I believed.