An individual file attachment can be as large as 500 MB[0]. It would make the JSON file too big to use.
Still, I do think that Bitwarden should warn users about it when exporting. Just mentioning it in the Help Center doesn't seem so helpful.
The backup would be too big to use if it included all the data it's a backup of? What?
I mean, I know "INSERT INTO files ('my-file.bin', X'CAFEBABE...')" gets it into sqlite, but how would a sane person get that content back out?
Not that performance or file size would matter in this case, BUT what using SQLite would allow is to use a single format for persisting all aspects of the password database, with immediate, programmatic, random access to all fields, including attachments.
But I also agree, that for this specific use-case, even SQLite is a bit of an overkill probably.
Finally, there is always https://www.passwordstore.org/ :)
sqlite3 -noheader -newline '' export.db "select data from files where filename = 'my-file.bin'" > my-file.bin
unzip 1PasswordExport-ILESALYKVFDNJH3K24FEO3QRHM-20220611-100457.1pux files/my-file.bin