I know that the introduction of the style system with Scrivener 3 is due to those who come from a word processor and want to continue working as usual.
Personally, I found the original approach the best, to separate content and formatting in the workflow and create the document with the compiler. This is how I still work today.
So I was wondering if you have thought about giving the user a choice between a WYSIWYG editor and a Markdown editor. Markdown is catching on more and more and is closer to the original idea after all. If there was the option in Scrivener, I would write all text as Markdown and then output them via the compiler.
You can certainly use Markdown in Scrivener. See Chapter 21 in the manual.
But Scrivener’s underlying format is RTF, and that is unlikely to change.
In my own experience, using styles fits in a lot more with the Markdown writing experience than you’d think, and it makes sense when you consider that styles are inherently semantic just like Markdown is. They thus allow for a way to add to what you can do with Markdown itself—which in some ways can be a bit limiting for some forms of writing. A simple example of that is provided in all of the stock MMD/Pandoc compile formats: if you add character styles for “Highlight”, “Addition” and “Deletion” to your project, you will find that they compile to CriticMarkup. The method used for accomplishing that makes it possible to generate all manner of advanced Markdown syntax, and even bespoke stuff you create for one article or book.
I wouldn’t go so far as to say that styles in Scrivener are a departure from its original intent. And if anything they were designed from the ground up to fit right into that ethos, even for those that don’t use Markdown to write. The fact that a “Block Quote” in the editor can end up looking nothing at all like the block quote you get when compiling with the Manuscript-Courier is testament to that. That’s a rudimentary example of styles working more semantically than as a WYSIWYG tool, but once you take that leap, and once you look at the options you have available to you in the compiler, you can see that there is a lot of flexibility in how styles can be used. They can even be used purely as a marking tool, invisible in the output, used only to flag bits of text one way or another.
I would say it is a mistake to conflate Scrivener’s styles with the thing you see in a word processor. That is the point of inspiration, and they definitely do integrate with that workflow for both input and output, but how they mechanically work and the ways in which you can use them are fundamentally different, and in my opinion, more powerful.