But unlike IDEs and programming language support, note-taking is inherently personal. There is no one-size fits all. I am more disorganized than otherwise, but I prefer separate tools for separate occasions. I like pen and paper for quick jot-downs and napkin math, notepad++/Sublime for quick copy-pastes, OneNote for $DAYJOB and org-mode for long term knowledge base and blogging.
I am sure real people exist who prefer one over the other on more than one occasion.
Being pessimistic, but I would bet it will be a walled garden. The solution will probably be key-in-hands and the easiest way for this is a traditional webapp. Not many people care about data ownership and bother dealing with their own file server.
See Notion, Google Keep, WorkFlowy, Dynalist, etc.
It's pretty clear from e.g. Roam's pricing that they're primarily targeting institutional licenses. They seem to have been pretty successful there, too.
Once Athens arrives, I fully expect them to eat Roam's lunch when it comes to individuals.
It's quite similar to the proliferation of code editors from 2005-2015ish. For a while, practically every language had its own IDE (for me, I remember using HaXe and FlashDevelop). Then, editors like Atom and Sublime came along, raising the bar. For the past five years or so, seems to be the default. The excellent extension system allows people to worry about features, rather than re-creating the IDE.
When it comes to note-taking, I expect the same thing to happen--we just need a good, open-source foundation. I fully expect that the winner will be a wrapper around ProseMirror [1]. See also ReMirror [2]
[1] https://prosemirror.net/ [2] https://remirror.io/