The fact that org-mode is tied to Emacs is both its weakness but also its strength. By sitting on the Emacs interpreter, org-mode imposes no limits to what you can achieve. The synergy with other Emacs packages is enormous.
You also forgot to mention one of the coolest features of Org: exporting your documents to whatever format you may want, e.g. html, latex, markdown, odt, reveal.js, - and it's possible to hack the export to fit your needs usually with modest effort. Here's an example of workflow to collaborate with Word users, for example: https://lists.gnu.org/archive/html/emacs-orgmode/2015-06/msg...
And here a recent blog post on exporting org to jupyter notebooks: http://kitchingroup.cheme.cmu.edu/blog/2017/01/21/Exporting-...