Rendering Org in markdown is a solved problem, but wanting Markdown as the source is nuanced. It's difficult to achieve because there's no single agreement or convention - Org is not just markup syntax, its headings have records with types slots: TODO keyword, priority, tags, properties drawer, clock entries, etc. - Markdown has none of this. A CommonMark heading is a line of text; the spec does not even define a subtree, so folding, refiling and archiving need tree semantics layered on top.

So, you need to invent slots. Logseq did exactly that - all the org-mode specific lines get lifted verbatim into .md. Obsidian did it differently with emoji fields or Dataview inline fields (or whatever they called). Neither produces portable Markdown. GitHub renders those files as literal noise. The portability benefit that motivated the move evaporates the moment you add the metadata you need.

And then you'd have to build a specialized parser - there's no equivalent of `org-element` for Markdown. Sure, tree-sitter helps to some extent, but you're still lacking a semantic layer that turns nodes into records.

In essence - for Emacs to treat Markdown as Org-mode, we need to change Markdown, once that happens (if ever) Emacs can follow. But at this point it is already such a mess, it's crazy. Take front-matter alone - it's not CommonMark, it is a Jekyll convention that each tool does differently, and it is per-file, so your unit of thought is limited to become a file. That is the Obsidian/Denote/zk design, it works - but it moves your outline into the filesystem. You lose refile, subtree archive, narrowing, cut-and-yank of a subtree, and "this TODO belongs under that project heading". Org gives you both: file keywords at the top, property drawers on every heading, with inheritance down the subtree that front-matter structurally cannot express.