I recently surveyed a writer about their software woes.
Response:
"I am a writer - fiction and non-fiction.
I haven't found good software to keep my notes, sentences, ideas, etc. in a way that helps me easily incorporate them into the project I am working on.
Oftentimes, I will come up with a sentence or a paragraph that I want to put in my story at a later time. It's just a moment - an idea- that comes up that I want to save for later use. Well, guess what, these ideas start piling up and I could have a huge pile of sentences/paragraphs that I will use to build my story. But hey, I don't know just yet where I want to place them to tell the most effective story.
I want a section in the particular file I am working on where I can keep these ideas instead of having a whole separate "ideas" file or worse, scribbled on a paper napkin.
I'd like to be able to easily drag and drop that paragraph/sentence from my ideas section right into my story without having to do the annoying cut and paste or worse, figuring out what file I saved that great sentence in.
I'd pay $130+ for it."
1. dragging/pasting ideas from an idea section directly into a writing program. This is where s/he's sitting comfortably somewhere actually working.
2. Scribbling ideas "on the fly" - which can happen anywhere (on the bus, walking down the street, etc..)
For the second, I like simplenote[0] and their tagging feature. Lots of support for various OSes. On 32-bit LinuxMint, I'm using nvPY[1] since simplenote doesn't have a 32-bit deb.
In order to solve both problems, the writing program could support something like simplenote via plugin. This way s/he gets their left-hand, drag/paste panel.
Note: also like https://standardnotes.org/ but could not get it to run on my older phone, no 32-bit linux support.