I've used those apps and the problem is that they only support a tiny subset of the format, and they can't support any of the features that require the rest of emacs to be present which is a lot of of the value.

If you're okay with the stripped down version that's basically markdown but different and that's fine but I feel like most people fall in love with org mode because it's so powerful once you get it going and all that power comes from emacs. So I get the argument that it's no worse than markdown but you lose so much of the magic.

Creator of Orgro here.

> they only support a tiny subset of the format

I think Orgro's parser[0] is pretty complete at this point. If you can find an Org syntax that Orgro doesn't support, please let me know.

However I should be very clear here:

> they can't support any of the features that require the rest of emacs to be present which is a lot of of the value

This is absolutely true and unlikely to change anytime soon. As I'm sure you know, parsing the syntax correctly is not at all the same as supporting all of the features built on top of the AST.

[0]: https://github.com/amake/org_parser

Both Orgzly-revived and Orgro support a lot more than a tiny subset of the Org format.

Do they support tangling of source code and export to all the formats that Emacs's Org-mode supports? Of course not. But they have all of what I expect for a knowledge-base on my phone, which is a lot more than Markdown was ever intended for.