In corporate settings with many non-public spaces it would be helpful to be able to delegate the management of group memberships to space admins in order to relieve confluence-admins of this task.

Example:
Spaces: X, Y
Groups: X-admins, X-developers, X-users, Y-admins, Y-developers, Y-users

As it is, only confluence-admins can edit membership in all three groups.

It would be better to be able to assign membership-edit privileges regarding X-developers and X-users to the members of X-admins and those regarding Y-developers and Y-users to the members of Y-admins.
That way, confluence-admins would only need to create the groups and assign privileges once and the space admins could do the rest.

It is, of course, possible to assign individual privileges to users per space, but using groups is much superior when a lot of users are involved.