At the end of this, having now gone through the five elements of what a player gets, technically, from a group structure, it appears that grouping itself needs to stay unless the games are completely redesigned. For example, in playing Wizard 101 I have been a part of a group many times without forming an actual group because the game is built around “casual grouping”. If a player is in combat, to join them you need only step into the combat circle. All combat is contained within a temporary group, four slots for your side and four slots for the enemy, and when combat is done the group is dissolved. But it is turn based card/deck played combat, and not the real-time hack and slash spell casting of the traditional Diku model.
Also, as brought up by many of the people I discussed this with, grouping does bring a social element with it, a sense of belonging and direction. There is just something about being invited to a group and joining that group that bands people together in ways that a random collection of people doesn’t have.
Anyway, I hope you have enjoyed this exercise.