Why does it have to be different? Org-mode is about a year older than markdown and there’s a whole ecosystem inside of emacs you can leverage (notebook-like cod

Why does it have to be different? Org-mode is about a year older than markdown and there’s a whole ecosystem inside of emacs you can leverage (notebook-like code execution with org-babel, literate programming, agenda/calendaring, etc.). You could probably build this all on top of markdown (although Markdown’s syntax is much more limited, something like Mediawiki markup would probably be better) but it already exists if you already use emacs.