Unless a course is set for "No groups" and "Force group mode" is ON, the teacher should be able to very quickly assess - without clicking - the group mode currently selected for each activity in the course. Such information can be critical - e.g. for controlling Forums and the visibility of posts, etc.

SADLY, in Moodle 4.0 the toggle group-mode icons, which were always (until version 3.11.5) displayed for teachers working in the editing mode, are GONE from Moodle 4.

In Moodle 4 it is NO LONGER possible to review the group mode of activities at a glance at all !  Removing editing via these icons is a good move - it has been too easy to manipulate and inadvertently change the group mode of an activity. However, in general, activity group mode status icons (or labels etc.) are very much needed by course teachers, and should be displayed for them on the course page BOTH in the edit mode AND in the non-edit mode (except when the "No groups" mode is forced onto the lower contexts by the course settings).

I hope this important facility of quickly reviewing the applied group modes can be brought back - in the better way described above - always visible regardless of the Edit / No edit status, yet without direct editing / toggling capabilities.