I suppose it depends entirely on what the account is securing.
My bank? Needs to be pretty independent of everything else.
Some random web store or something like Kickstarter? The only reason I care about those accounts is to track orders or for the convenience of not having to re-enter credit card info. The risk of losing my Apple account because ??? and dealing with recreating those accounts is negligible. In many cases I just use guest login for exactly that reason.
The convenience accounts are the ones I might use Sign in with Apple for. The bank? Not so much. But I won't trust Google or Facebook with even the convenience accounts.
I would also use something like this Touch ID on the web feature for 2FA, particularly if the only other options are SMS or email.
My bank? Needs to be pretty independent of everything else.
Some random web store or something like Kickstarter? The only reason I care about those accounts is to track orders or for the convenience of not having to re-enter credit card info. The risk of losing my Apple account because ??? and dealing with recreating those accounts is negligible. In many cases I just use guest login for exactly that reason.
The convenience accounts are the ones I might use Sign in with Apple for. The bank? Not so much. But I won't trust Google or Facebook with even the convenience accounts.
I would also use something like this Touch ID on the web feature for 2FA, particularly if the only other options are SMS or email.