It's useful when working with remote servers that may not have a graphical interface at all. There's rsync and network drives are sometimes an option but it's very convenient to just ssh into a server and edit/view with vim directly.
In the cases of vim/emacs, people who dive deep enough will often find them superior than <previous fav text editor>.
In the cases of vim/emacs, people who dive deep enough will often find them superior than <previous fav text editor>.