To easily distinguish/access bookmarked headings when navigating long notes, such as course notes with many headings and subheadings.
Just like you would use actual bookmark stickers on a book/notebook.
It’s good to collect headings in bookmark folders and this feature would make reviewing them in context easier.
Small bookmark icon next to the headings in core Outline view.
And to be able to bookmark/remove bookmark with right click menu.
Adding emojis to the headings
It’s a quality of life/ux request to be honest, just accessing the already existing functionality easier.