I’ve been using SQLite with HashBackup for 12 years, and it’s been super reliable. There have been 1 or 2 problems reported that ended up being hardware related, and I’ve seen a couple myself: a USB drive wrote 512 bytes of zeroes in the middle of a database, which had to be a hardware problem because the sector size is 4K; and I had a bit get flipped on a db record on a Macbook Pro. That was bad RAM.
It’s unfortunate that all computers don’t come standard with ECC RAM these days - another source of problems.
One other gotcha about SQLITE: if it has an active journal or wal, you cannot make a copy of the db file with OS commands. These two files go together and with OS commands you can’t atomically make a copy of both. You have to use the .backup command in the sqlite3 CLI or the SQLite backup API to get a good copy if there is an active journal or wal.