Security matters, users who want choice have to take responsibility, users that don't can just use Apple.

"What happens when I go to the same site on a different platform?" = "If you meant device, then Chrome has a feature to allow you to use a different device such as a NFC YubiKey"

"What if I can't use cross-device authentication because I'm on a locked-down work machine or one that simply doesn't have bluetooth?" = "Good, Passkeys are doing their job correctly and you cannot export credentials"

"What if I want to consolidate them all in one platform just for the sake of being organised?" = "Then log in and add more passkeys to things rather than copy-pasting passwords everywhere"

"What if I lose or simply don't have the device with a certain passkey near me?" = "You should have multiple passkey's or use the various cloud versions that exist"