I actually think you've got the wrong end of the stick here because you are likely talking about two different security methods (passwords vs passkeys).I think you're discussing a different issue? If I pick up my (work) Pixel and go to change the pw to my Google account, I need my Google pw to do it. If I select Forgot my Pw, and go into Account Recovery, it requires my actual fingerprint on the screen lock (not the device passcode), or other recovery options that the thief may not have access to (i.e., a non-Gmail email address).
Meanwhile, on my iPhone, I can change my Apple ID pw simply by entering the device passkey.
Let's assume your iPhone is setup as a passkey for your Google account (as well as your Apple account).
To reset your Google password from your iPhone you would navigate to the Google website, login by authenticating with your device biometrics or passcode, then change the Google account password. At no point in changing that password is anything other than the iPhone passcode (or biometrics needed).
The process is the same for changing your Apple ID password (except you can do it on device rather than navigating to a website).
This is how passkeys work. Your trusted device (the physical iPhone, iPad etc) is the 1st factor, the passcode (or biometrics) is the 2nd factor. That's in comparison to traditional password method which is password (1st factor) and 2FA code (2nd factor).
Last edited: