It opens up a navigable directory tree in the Vim window. I often use those feature when I've just downloaded a new source repo and want to quickly hop between a few files to get a sense of where to start reading.

It actually provides a pretty good interface for choosing files from a directory. Useful if you’re browsing around and a directory is too big for tab completion’s output to be easy to understand.

You get a directory listing which allows you to navigate to the file you want.

If someone creates files with control characters opening the containing directory in vim will let you delete the offending file, works like a bootleg file commander you don't have to install