There are definitely lots of 'notebook' products out there, and they all excel in their own ways by making different trade-offs. Standardnotes, Obsidian etc. support user-side encryption but in my opinion they are not as versatile as they could be. I am also keeping it plain-text only for a few reasons that are important to me:
1. keep the UI straightforward and efficient to use 2. provide seamless integration with popular text editors (emacs, vim, vs-code) 3. support some nice functionality for editing structured text like markdown and org (like org-mode in Emacs)
I can consider some hybrid approach in the future if the 3 things above are not affected.