Sibling comment already addressed the readability of the source, but I'd like to ask what rendering you mean exactly?
The "rendering" I see in an open org-mode file right now is a) coloring and b) collapsing. So apart from hiding and coloring things I think what emacs shows is exactly the source, at least in my configuration. Did I miss something?
When I last played with it (Emacs + Org) I had options enabled which hid much of the markup entirely (e.g. the **) and applied various styles to express the intended structure, and it was lovely, much more than just coloring. Nothing I'm saying is without love for Emacs and Org, more just sulky acceptance that tools can add additional mental overhead, even if they're cool, and this seems to be the opinion/philosophy of modern tools etc, VSCode/IDEs/Web-based IDEs etc.
So.... when I tried to use Org in VSCode, Vim, Notepad etc, it just sucked. Not even a comparison. In that case, Markdown was better. Maybe I'll look at it again. But like the OP (in the sense of making up my own thing) I have dabbled in creating my own clone of Org-mode based on a Markdown spec.
Hmm ok, I never have these options on. For no particular reasons other than that they don't seem to be the default (or something's wrong with my config), and I never missed any additional application of style.
So it's possible that I just got very much used to how org-mode "source" looks.
Yes, for task management and for any other applications, Emacs offers programmable views of Org files.
A popular view of Org files that comes already builtin in Emacs is the agenda view.
The agenda view lets you query all todos, incoming deadlines, scheduled appointments, etc. harvested from a list of Org files.
For example, I can quickly see all todos, incoming deadlines, scheduled appointments, holidays etc. for an arbitrary period of time, say week 40 of 2022.
The "rendering" I see in an open org-mode file right now is a) coloring and b) collapsing. So apart from hiding and coloring things I think what emacs shows is exactly the source, at least in my configuration. Did I miss something?