Pandoc is to me the single most useful visible Haskell outcome. The entire language would be justified to me by this polyglot format translator

Good stuff but criminal to not mention Obsidian

Why would I buy a subscription to a markdown editor when Obsidian exists

Because you just want an editor and Obsidian is not an editor?

I think markdown's success comes from it's open and simple standards. When things can be easily parsed and rendered, anyone can build tools that use it. When things are interoperable, the tools can change but the format lasts forever.

Their main product -- Windows and Mac platforms only:

https://ia.net/writer

Can't seem to find screenshots. Anyone used it?

I tried it out. I found I prefer my editor to be less visual, like vi or emacs. I write raw markdown, and occasionally look at a preview window. Structure is everything for me, even minimal styling distracts me.