You are correct in that quite often who implements provider vs consumer depends largely on market position. There is technically no reason Apple can't become a consumer, other than they aren't interested in doing so. Also consider that, should Apple choose to eliminate your account, then you've lost whatever you use Apple to sign in with unless those downstream providers offer some kind of recovery mechanism.
> Also consider that, should Apple choose to eliminate your account, then you've lost whatever you use Apple to sign in with unless those downstream providers offer some kind of recovery mechanism.
Yes, some kind of recovery mechanism, some ability to set a local credential post-registration, or some ability to link and unlink external accounts, e.g. Sign in with Apple, then link your Google, FB, and Github accounts. Then, if you lose access to your Apple account, you still have additional options for authentication.
The latter two options are something I wish more organizations offered..!
