Support was first offered in May, but now Google suggests it as the default choice.
Passkey is some sort of specific unique key to a device allowing to use a pin on a device instead of the password.
But which won't work on another device.
Now I don't know if that key can be stolen or not, or if it's really more secure or not, as people have really unsecure pins.
You link to articles about law enforcement hacking phones to get data as a reason not to use biometrics? If they are hacking your device it doesn't matter if you use a password or a fingerprint.