> And no, because it depends on how users setup and use their AppleID and its passwords/security/devices.
Can you elaborate what the issue would be? I see that the AppleID password could be a weak link, but that's mostly mitigated by 2FA.
> if 1Passwords decides to share the private key
I'm not aware that they could do that. Their servers have no knowledge of either the password or secret key. Authentication happens via a zero-knowledge proof.