Passkeys do not require you to have an ID and Password. Passkeys use encrypted keys established between you and the website or wherever passkeys are supported.
Passkeys are much more secure than passwords. You don't have to remember them or use a password manager. Passkeys are not vulnerable to phishing attacks and easy to guess passwords.
Passkeys do require biometric authentication like fingerprint or facial recognition (TouchID or FaceID).
If a website asks you if you want to switch to a passkey my advice is to do it. Eventually passkeys will become mandatory.
All the big tech companies, Apple included are pushing hard for Passkeys instead of passwords for more security.