I guess my point is that in your example, Joplin is the same. The feature hidden behind a paywall is for them to host the sync function for you. Both Joplin and Obsidian offer that. Yet you can roll your own method using Syncthing, Nextcloud, etc for either of them. If it’s FOSS or not that’s a deal breaker, I get it. I gave Obsidian a pass in that regard since the file format is so wide open and universal.
You may want to keep an eye out on these two as well. Both are missing some features now, but have them on their roadmap:
can’t self host the mobile app side of things, but the desktop versions work without an account and use markdown file format like Obsidian (and others)
Can’t self host yet, but on the roadmap. The dev confirmed to me that there would be no fee tacked on for self hosters once released, something that either Standard Notes or Simple Note does (can’t remember which).