The advantage of "Sign-in with Apple" being interoperable means that networks of relying parties (e.g., national research and education networks) can readily pr

The advantage of "Sign-in with Apple" being interoperable means that networks of relying parties (e.g., national research and education networks) can readily provide Apple customers access to high-integrity services. Both kinds of LOA—identity proofing and identity binding—are really difficult to do without secure hardware, and it could drive Apple product sales if they make LOA easy to do with their stuff (like TouchID or FaceID).