There are already (to me) very useful places where I can get OneNote where I can't get emacs -- Android and iOS. I don't expect to ever see Emacs on iOS, and I tried it on android but it doesn't work well at all.
Not sure why you think emacs org-mode will be around forever. While I'm sure emacs will be around forever, I've had vim (not emacs, I don't use it I will admit) extensions which rotted as new versions of vim came out.
Not sure why you think emacs org-mode will be around forever. While I'm sure emacs will be around forever, I've had vim (not emacs, I don't use it I will admit) extensions which rotted as new versions of vim came out.