How to re-link collections to scene To clean up my scene, I used Right-Click > Unlink in the Outliner, but now I want the collections back.

I can find them by switching to the Blender File context in the Outliner, but the Right-Click > Link to Scene doesn't appear to do anything.

Instance to Scene makes something that acts like a Collection Instance, so I can't edit the contents.

I also can't click and drag, or copy paste.
What am I doing wrong?
You can open a second outliner view and drag and drop the collection back to the view layer.

Here from Orphan Data to View Layer: