Use of XML can facilitate readability if the schema and tags are appropriately designed.  However, I'm far from convinced of its superiority in all areas. 

The main issue for me is that as a data exchange format, it tends to be quite verbose (in terms of the ratio of data bytes to total bytes).  Because of this, when used in interprocess communications to exchange data, performance can become an issue.  And when used to create files for other applications, the files can be very large in proportion to the data they contain.  I'm an old database dog and still like fixed-byte or CSV format for stuff like that, because it's more parsimonious.