Are you referring to a physical lockbox? Because if so, that is certainly not as secure as your bank account, because criminals could not drain your bank accoun

Are you referring to a physical lockbox? Because if so, that is certainly not as secure as your bank account, because criminals could not drain your bank account by breaking into a bank, nor could your account’s funds be lost if the physical location were destroyed by a flood or other disaster. Even if you are referring to digital storage managed by the bank, presumably competently enough to avoid data loss, if that data is exfiltrated your wallet will be drained. It would be very difficult for a hacker to irreversibly drain your bank account (given the type and terms of the account, but will apply to most savings accounts), due to the protection and delay systems in place meant to catch fraudulent or unauthorized activity. Note that this definition of “unauthorized” actually means “not authorized by the human being who owns this account”, instead of the crypto definition of “not authorized by someone who knows the correct secret”.