There is actually one use case for it. I create a yearly backup that i distribute across my friends (mostly via CD-ROMs) which include all my files that i can’t afford to lose, like encryption keys, keepass database, crypto wallets (everything that isn’t encrypted data gets aes-encrypted via gpg and a 512-bit key which is stored in the keepass database). But if say a malicious actor gets access to it by social-engineering they could start brute-forcing the keepass-database (good luck though with my passphrase and 10-rounds of argon2 with 4-threads and 4gig vector size), by splitting it into fragments that vector would be closed.

I’ve always liked this, it has pretty much everything you could want in a personal project: a catchy name and a whimsical idea that is just on the edge of being actually practical.

This basically just means the files themselves become the authentication.

I don’t see a singe use-case, where you couldn’t just use normal private-key encryption and just save the private key to a file somewhere else. And if you want to distribute it to multiple locations, so that you need all of them, then there are also encryption methods for that.