There is a difference between orphan pages, pages without internal links and pages with internal links and pages without any external links
Orphan pages are pages with no external and internal links.
While that report is important, you also want to know how many pages on your site does not have any external links whatsoever.
External links are helpful if your content is informative, and valuable sources should be added to provide facts and data to support your content.
Identifying pages without any external links can help you audit and review those pages, so you can add external links and build up your authority.