[jp_sc]

Is not a built in text editor, is a command to open programmatically your default text editor to edit a file (new or existing).

There are several cases when you would want to do that, for example, think on the git CLI, that opens one so you can write a commit message, etc.

And is not only about using the EDITOR variable, most non-programmers doesn’t have one defined or it points to vim or something equally terrible for non technical users.