When Apple announced their forthcoming iOS 13 "Sign In with Apple" service the public rejoiced! Security guaranteed! Privacy preserved! Now, the technical implementation details are coming out we see what a disaster it is in the making. I'm glad to see my friends over at the OpenID Foundation have taken deep technical dive into how the service is implemented and identified a ton of software defects. The list is long. See for yourself here.
It's always been a beef of mine that Apple has thumbed their noses at standards that would guarantee the image of their forward thinking about authentication and the integration of modern MFA options. I love their products. Just not happy with this shortsightedness.
I remember back when Microsoft messed with Kerberos in much the same way ...
And kerberos is still going strong all of the years (since late 1980's)!