Correct. Nothing is centralized about Passkey (other than where you may choose to store your authenticators). Each site gets a unique keypair. If your keypair i

Correct. Nothing is centralized about Passkey (other than where you may choose to store your authenticators). Each site gets a unique keypair. If your keypair is compromised you can delete it on that given site. Passkeys is more or less just a more convenient implementation of FIDO2 or the like, as you'd traditionally have with a Yubikey token. Instead you move it to a supported password manager or mobile device. If you want to try it out go to https://passkeys.io https://passkeys.io on your Android or iOS device. I do believe Passage is more or less what Passkeys is/already was.