I have one use for a command-line FTP app.

In my business (television production), I have to occassionally FTP files to an (ancient) piece of equipment where the destination directory doesn't actually exist - it's a phantom directory that converts the standard file I'm transferring into it's own proprietary format. The destination directory doesn't appear in GUI-based applications.

Fortunately, not only is there a command-line FTP app in Windows, but this once-cutting-edge piece of equipment is being phased out almost entirely from my encounters.

Just one example...