The biggest strength is not the file format or basically the org mode markdown flavor. The strength comes from integrating it with all the other Emacs stuff. Org-babel for example, think of it as a suped up Jupyter notebook. And it integrates with the emacs calendar/agenda. The closest you can get is maybe Obsidian's Dataview plugin, but it absolutely pales in comparison to Emacs Org.

It is one of THE main reasons for me to use Emacs.