I think, the major appeal of it is that it does everything.

Lots of "productivity"-applications are either TODO-lists or meant for note-taking or good for writing down concepts or are knowledge bases.

But you can't really separate these. Often I'll write something down and later realize that I need to do xyx for that. Or that I want to schedule a reminder for this note.

Other times I write something down just to have it written down somewhere and I won't want to see it again until months later. But if I just write it into a random .txt-file, I'll probably never see it again. With it being in the same place as my other notes, todos etc., I will actually find it again.

And other times, you might have this dumb idea for a thing. And then you add some more ideas to this idea. And before you know it, you've written down the entire concept for your next software project in your notes-application. When this happens to me with OrgMode, I really don't mind. Its plaintext-format is just as readable as MarkDown for this use-case. I might very well stick this OrgMode-file into the software repository.

Also, sometimes I will find an article to something in my software project concept and want to note it down there with a reminder to actually look at it. OrgMode allows me to do that.

Eventually this becomes a lot of information in one place, but OrgMode itself has lots of tools to organize that: tags, priorities (from A to whichever letter you like), notebooks (=different files), states (e.g. TODO, DONE, NOTE, and again whatever you like), scheduled times, deadlines, recurring tasks etc.

And then there's obviously also parsers like the one in this post. They can do whatever they want with the plaintext you have there.

Personally, I mostly use the Android-app Orgzly. It has a widget with a simple DONE-button for my TODO-usage. It can throw notifications at me. And it has a really powerful search-feature, allowing to save specific searches and for example select them as the listing to display in the widget. E.g. I only want to see notes with the state "TODO" that are scheduled within the next three days.

I will admit that it's a bit of a rabbit hole, but task/note management in general usually is and this feels better than my previous solutions.

Especially also the fact that it is just plaintext-files that I can sync and backup easily.