The outliner work, especially since the move to Collections, has been impressive. I have been examining the possibility of a [potentially optional] usability idea: Additional indicators for the active object hierarchy, and possibly object-relations (linked duplicates and outliner-linked-instances)
Reasoning:
It can be difficult to know, at a glance, where your object is in the outliner. Num . to actually jump is often not desired.
Consider the following… my object is in “Arch Parts”, below the view:
I was thinking the “parents” (containing objects and parent) structure used to have some indicator showing, “it’s inside me” (something more clear to a user than a subtle highlighting of the parents/collection):
The line-arrow indicator (or whatever), could scale for the current view, but give instant recognition to the user:
It could possibly flip (interactively) upon scrolling, or have a consistent line, maybe with highlighting changes to reduce a feeling of clutter):
Maybe Linked Duplicates can also be indicated (that has always seemed like a big need). Cyan shows linked duplicates’ presence. Yellow is showing the outliner-linked-instances:
