I know it does not. It's in the Cloud. I was referring to SIM and phone number when I was thinking potential way to recover.
Can you explain how a person can login into their iCloud and recover their iCloud Keychain after they have lost their only Apple device (iPhone) if Apple Passkey needed to access iCloud?
>To recover a keychain, a user must authenticate with their iCloud account and password and respond to an SMS sent to their registered phone number.
In other words. If you lose your iPhone (containing your SIM) you can't get access to iCloud or iCloud keychain until you have a new SIM with the same phone number from your carrier.
If you travel in a foreign country and lose your iPhone you are locked out of "everything Apple".
You can register VoIP and landline numbers as well, and nothing says the number must be yours; you can also add the number of a trusted family member or friend.
You can choose which preregistered number to send a message to (or to be called with a recorded voice) in the event you need access to your account in an emergency.
This also implies you have no other Apple devices which are signed into your account, as they will receive a code by default.
SMS works with password access as 2FA it's part of plan A in recovery.
None of the methods you mention are something that should be expected from normal users. Or they don't work when traveling. I travel a lot.
"There is a way you could set it up" does not mean Apple has a good solution. As I'm a person without family and only one iPhone I stay away. People who don't pay attention are fucked.
But they're in your iCloud Keychain. You should just log in to iCloud and have them again.