Joplin does have an automatic backup plugin. Which I recommend enabling for obvious reasons.

Also, moving to different versions is kinda tricky sometimes. No matter the software, when moving from very old version to a new one, I always keep the old one around until I’m certain the stuff was moved over cleanly.

But yeah, having the notes in a database is definitely not as robust as the plain text storage. Wish Joplin would just let you say “I have a git repository”.