Unlike most 3rd party password vaults, MyPass Password Vault is 10% Open Source and Offline. Your data is saved and stored locally within the same directory you run MyPass from, and nothing is sent anywhere else on the internet.
Either as a backup to an existing password manager like BitWarden or LastPass, or as an outright replacement, I recommend keeping MyPass on a USB dongle so you're never without your password vault.
As it's a completely offline backup, you can also store your login information for third party password vaults, in case you ever accidentally get locked out.