Why does the permission setting in groups of "Admins Only" not include Co-admins or Group Admins?

I just learnt that the group permission setting of “Admins Only” does not include Co-admins or Group Admins. Given, it seems that you can only have one Admin per group, this should be changed to “Admin Only”. Also, there needs to be a permission setting between this and “Group Members”. If the group is company-wide, we don’t want all members being able to provide the entire organisation access to folders that were previously restricted.