All of these problems are solved by implementations that have been around for ~15 years. Eg: LUKS. It doesn’t use the passphrase to derive the key, but rather

All of these problems are solved by implementations that have been around for ~15 years. Eg: LUKS. It doesn’t use the passphrase to derive the key, but rather encrypts the key using the passphrase. This allows users to change their password and allows having multiple users with different passwords.