Not quite sure what the point is

As far as I can tell from using this plugin and reading its documentation, all it does is it dumps the “subtitle” wherever you add <?php the_subtitle(); ?>. Then you have to style that, such as bu surrounding the PHP tag in an <h3>.

How is this a lot better than just starting the post with a heading? That doesn’t require figuring out how to add the tag (locate “Single Post” in Appearance -> Editor), or where exactly to insert the tag (before the_content, for example) – both things that aren’t mentioned in the docs.