As per the AppMenu retirement initiative the appmenu should be removed from System Monitor.
As for the moment based on the wiki page it's not clear for me how to achieve that in context of system monitor, which:
- has in-window view navigation using the stack switcher from the headerbar
- has a view menu only for the first view (Processes)
The View menu should probably stay visible for all views, but what should happen with the view-specific items? My option would be that they go into a separate togglebutton menu (which is only visible for the Processes view).