I feel this cannot be overstated. I am finally moving from a 2009 Nokia N900 to Android only because I know I can run Emacs+org-mode in Termux on it, and I can get a hardware keyboard.
Emacs is central to the org-mode experience because all of the goodness is implemented in emacs lisp. Most everything I do with it is an extension of that (custom capture templates, todo lists and agendas, etc.) A standalone tool just wouldn't cut it for me. If I need to share something I've worked on in org-mode, I'll export or use pandoc to get it into something useful for a non-emacs user.
EDIT: I also don't find org-mode difficult to read outside of org-mode, but I'm also pretty familiar with it. It does frustrate me when I open up notepad++ or something similar to check an org-mode files and my tables don't format automatically.