Plain text is the most timeless and reliable way to store words.
Plain text is universal and non-proprietary. It doesn't require any special editors, ecosystems, platforms, and there’s no DRM baked into it. Your notes are readable wherever files are readable, which is everywhere.
Plain text doesn't break with software updates. If the file exists, your note exists.
Plain text is copy & paste-friendly. It doesn’t drag fonts, weights, or styling along with it. It assimilates into any environment in which you paste it. Plain text is the raw ingredient on your cutting board that isn't flavored until you throw it in the pot with the other ingredients.
Plain text comes in small file sizes. It's easy to store, copy, transfer, and back up.
Plain text respects your future self. Modern note-taking apps assume that they’ll be around forever and you'll be invested in them forever. Plain text assumes the opposite. Your tools will change, but your notes shouldn’t.
Most importantly, plain text is ownership. The further away you move from plain text, the further you are from owning your notes.