Hi, @KB. Dang. I keep starting drafts of this post, and they keep coming out as rants that will ignite a flame war. 
Not my intention.
For me, Scrivener could change in the following ways and still be my go-to writing software. I will say that the corkboard / synopses are core to how I use Scrivener; the Outliner, less so but still important. I would be disappointed if stacked corkboards disappeared!
- I don’t use Scrivener as a research repository, so don’t feel that users have to be able to dump everything into Scrivener in order to keep me as a user.
- There are many similar sets of features that enable users to do almost the same thing: for one example, the term “notes” can mean about seven different features – and has in various forum posts. Please feel free to delete near-duplicates. I will cope somehow.
Regarding ease of sync: have you looked at how Ulysses handles its external folders feature? It’s a different sync paradigm that might be a better fit for Scrivener projects. It can be used with any cloud service that’s accessible via the iOS Files app, including but not limited to iCloud, Dropbox, et al. It might be easier on Windows users. It would involve changes to the Scrivener project structure, but what wouldn’t?
Finally, some suggestions about UI. You are right that users seem less and less inclined to read doc – and the same can be said for developers wanting to provide it! The problem I see with Scrivener is that when I start an empty project, I get a document pane that looks very similar to a document pane in Word, or Pages, or even TextEdit. The Tutorial looks like a polished Word doc. The temptation is to assume that that I already know 90% of how to use this software, when in fact I probably know about 10%.
My suggestions: make it obvious from the start that there is a learning curve. Don’t call styles “styles” unless they’re to be used the way styles are in Word – think up another name. Put those “outline boxes” around them; lose the way to make a style without them. Hide the format bar by default, and bury how to make it visible in the menu system, except possibly for character attributes and a “styles” pulldown. And somehow apply changes to the default formatting automatically to all extant documents in a project. Do it to different projects as they’re opened.
And make “as-is” a hard-to-access compiling option.
In short, I suggest you make Scrivener look and act more like a markup-based writing app. No one expects to send what they see in the Ulysses editor to their audience, be that audience readers, a professor, or a judge. I suggest it be the same with Scrivener. I know that this is contrary to how you envisioned Scrivener in the beginning – I’ve butted heads with you on this before! – but I believe it would help new users have realistic expectations.
Of course, you will do exactly as you decide, and I will likely remain your customer and loyal user.