Case in point: one of my favorite productivity plugins is a full-fledged Kanban board. It has deep integration into Obsidian features:
Unlike Obsidian, Plume's editor is a block-editor. That gives it the flexibility of Notion (to put advanced blocks like Kanban within the same document, to do drag & drop, etc.) with the performance of native apps by utilizing Qt C++ and QML (actually, Plume is 4x faster than the fastest native block editor on macOS - benchmarks on the website).
EDIT: Also, Plume is opinionated compared to Obsidian. That means much better ease-of-use at the cost of extensibility. I believe this is a trade-off worth to be making. I know first hand the intimidation of starting to work with something as complex as Notion or Obsidian. Plume is taking the block editor abilities of Notion with the familiar Apple Notes UX/UI while all the data is still plaintext underneath.
But I recently discussed my reasoning to go close-source[2]. I've been working night and day (every day) converting 4 cups of coffee into code for the last 4.5 months to create Plume. I don't want to risk not being rewarded sufficiently for it. But, I'm 99% sure that I'll either open source the core block editor or the entire app in the future.
Why withhold the remaining 1%? If you aren't so confident about your decision to open source, there's no need to commit to that decision now.
It's good that you are leaving the door open, but keep in mind that if some folks suddenly become successful with a service that can turn any GitHub repo into a nice looking SaaS, at the click of a button and for a super low fee, I'm pretty sure you'll be hesitant to open source all your hard work so it can harvested.