That's a fair point, and I wouldn't argue that XYZVault is strictly more secure than a well executed 3 key geographically distributed setup. If your threat model is maximizing security and you're comfortable managing three separate locations, that's already a strong solution.

The advantage we're trying to provide is convenience without giving up self-custody.

With XYZVault, you still control two keys, so we can never move your funds on our own. The service key simply acts as a backup key when you have access to one of your keys but not the other. For many people, maintaining three hardware wallets in three separate locations is operationally difficult, expensive, and increases the chances of losing track of devices, descriptors, backups, or recovery information.

The other aspect is privacy. Many collaborative custody providers require KYC or collect enough information to know exactly who you are and how much Bitcoin you hold. Even when databases are encrypted at rest, that data is typically stored in plaintext within the application and can be exposed if the platform is compromised.

XYZVault takes a different approach. Your descriptor, xpubs, labels, vault configuration, and other sensitive metadata are encrypted locally in your browser before they ever leave your device. The server stores ciphertext, not plaintext, and does not possess the key needed to decrypt it. As a result, a database breach doesn't reveal your balances, transaction history, wallet structure, or other vault data because we don't have access to it ourselves.

So the value proposition isn't "replace perfect OPSEC with trust in us." It's reducing the operational burden of managing a multisig setup while minimizing the amount of information the service operator can learn about you.