There are ways to get around the lockin just like with Evernote. It's not easy nor clean as with any attempt to migrate but one way to do it is via Pandoc and L

There are ways to get around the lockin just like with Evernote. It's not easy nor clean as with any attempt to migrate but one way to do it is via Pandoc and Lua Filters to transform custom syntax to other forms. For Obsidian, I was able to write a Lua filter for Callouts to convert to Hugo shortcodes/Quarto's callouts based on someone's previous work. I also want open-source for PKM software but I realized I value getting things done more if there were no near alternatives for my use case. I tried Logseq but it's straying even further from vanilla Markdown than Obsidian and is not as well-polished.