For me, the turning point for Obsidian was their Canvas feature. That was a big move beyond the initial design of it being an excellent editor for a directory or markdown files that supported links and all the other cool things you can do with a basic directory of files and a few conventions. Nothing proprietary, nothing much beyond the directory of files aside from a preferences store. IMHO, Canvas and beyond should have been a new product.
If Obsidian was open source I would have been tempted to fork it at that point.
Your accountant was calling you at late hours asking you what the hell was going on with your note taking expenses?