I am shocked how many ppl think synchronization like syncthing act as a backup.
No synchronisation is not a backup. If you accidentally delete the database and it syncs across all devices then the database is gone. If something is broken and overrides multiple times then the history if it is enabled is also gone.
Pls use proper backup methods to backup your database.
Edit: I sync my database also with syncthing across devices. But to back it up i have on multiple clients system backups running that include the database.