The reason why many Chess.com groups do not give super admin positions to anyone but the founder
If you browse through all of Chess.com's groups and teams, you probably notice that many only have one super admin, probably the founder. Premium members creating groups typically will do this, notable exceptions are Funtastic Chessmates! and aabbccdd.
There are several reasons why, the most common one being that if a super admin position were given to someone else, that person can potentially hijack the control of the group; it's one way for Basic members to "create" groups. The hijacker makes everyone else not a super admin, and bingo the group is his.
Other reasons include that the group has only a single member, that the group isn't one with lots of vote chess and/or team match activity (as admins and super admins manage), and that the group is a special one made by Chess.com staff.