Uses of XML?

We hear so much about the benefits of XML, but our company has yet to encounter a business situation where XML was required or we considered using it. None of our business associate interfaces have mentioned or requested that we share data via XML.
Still, we feel we may be missing something or not fully understanding XML. Does anyone have any suggestions on where we can review some real-world uses of XML to better solve a business need or any other suggestions on how or why we should be exploring/using XML?

Currently, all our interfaces with our business associates use defined fixed length record formats.

Thank you