You are right that Microsoft Office, Google Apps, and Libre Office are all fine for 98% of all users' needs.
Microsoft office does more. If I were to produce a book with proper front matter and index, glued together from multiple chapter documents, I would choose Word. But Microsoft Office does not work collaboratively as well as Google Apps, which were born cloud-based. Microsoft Office is laggy and fails completely with large numbers of collaborators (i.e. 20+ simultaneous editors). But these use cases are for 2% of users.
Microsoft office does more. If I were to produce a book with proper front matter and index, glued together from multiple chapter documents, I would choose Word. But Microsoft Office does not work collaboratively as well as Google Apps, which were born cloud-based. Microsoft Office is laggy and fails completely with large numbers of collaborators (i.e. 20+ simultaneous editors). But these use cases are for 2% of users.