[c-smile]

WYSIWYG HTML/CSS is limited for the simple reason:

Given HTML/CSS as input you can render it precisely (produce pixels on the screen). Mathematically speaking, the task of rendering is determined.

But WYSIWYG editing essentially is an opposite task: by given/desired set of pixels to synthesize HTML/CSS structure. And that task is not determined - different HTML/CSS constructs can produce the same set of pixels. That's why there are no acceptable/usable "WYSIWYG web site editors" - WYSIWYG is feasible only on reduced scope -limited set of HTML/CSS constructs that you can use to achieve 1:1 source/rendering ratio.

And that is what Markdown is all about, again, mathematically speaking - its rendering is in 1:1 relationship with its source.

I am experimenting with Markdown too: https://notes.sciter.com/2017/09/24/markdown/

but it is far from ideal either.