If you search 'Markdown' on HackerNews, it'd seem like the 'market' for markdown editors is fragmented: there isn't a single dominant editor yet. I think every week there's a new editor posted (Joplin is an exception given that it's been here for a while). Why is that the case?
I think it is because each comes with its own opinionated workflow, and missing features. Each has a way of writing markdown/connecting notes that is novel, which means each other option is missing that feature. A take away from this scenario might be that this design space is wanting for a meta-editor. Some tool which allows feature creation in the same context as these markdown/note tools. An analogy might be that…
[1] https://prosemirror.net/ [2] https://standardnotes.org/extensions