Yeah, to expand Obsidian is almost exactly what you're describing. It's a wiki-like software that works entirely on markdown and data on the file system. Has similar functionality to Notion but feels more like an IDE
Gotcha. I think I never dug into it because normal people generally don’t want to write in Markdown. The effort in doing that and manually managing cloud sync isn’t worth it. Apple needs to build it with WYSIWYG and have it work out of the box with iCloud.