Yes, it would be very useful to be able to collapse the namespace tree.
If a parent node has many children is difficult to see the siblings of the parent at the same time because there is too much distance between them.
I would like that page to be a fully editable outline, so I could add notes about what the different branches mean. I could add a note about why I organized a namespace hierarchy the way I did.
Couldn’t agree more. Also, I wish namespace could be displayed in the sidebar for quicker viewing. Currently it is displayed at the end of the article, which is very inconvenient if the article is long or has many references
see the picture below: