SQLite won't stop working but your format is proprietary. A markdown can be understood even without rendering to HTML but your tables are useless for an user without your app.
> SQLite won't stop working but your format is proprietary.
As far as I can tell, the whole app is open source (AGPL), and sqlite is obviously open source as well. I agree that markdown is more portable, but this setup is far from proprietary.
I may not have made the same decision (I love having my notes in markdown), but I think OP was quite thoughtful about it and has made an informed and reasonable decision.
You can likewise encode proprietary information in Markdown, in the sense that it can be readable but not necessarily understandable by another application that understands Markdown. Like say for example my application allows for tables that include formulas in cells. Perfectly human-readable Markdown but probably won’t have the same level of fidelity in another application.
A key idea of Eidos is to make each table a real SQLite table, so users can view and modify it through other software or visualize it with tools like Metabase
This is why I use RTF. It is considerably more flexible than Markdown (which can't do basic stuff like making text red), but not a proprietary format. The application I use (DEVONthink) supports a number of formats including Markdown, HTML and RTF, and documents how to get at the raw files if the application ever becomes unavailable. No use of a proprietary database format. This is for my 30-year files.
I also use RTFD in the same application. This is a variant of RTF which can have embedded images. It's not universally supported like RTF, but there are sufficient third-party editors to leave me confident that I will be able to get at the information. This is for my 5-year files.
As far as I can tell, the whole app is open source (AGPL), and sqlite is obviously open source as well. I agree that markdown is more portable, but this setup is far from proprietary.
I may not have made the same decision (I love having my notes in markdown), but I think OP was quite thoughtful about it and has made an informed and reasonable decision.