After the standardization of authentication SMS, Apple continues in the security of identification. Apple is now a member of the Fido Alliance which advocates 2-factor authentication to replace the password.
Fido Alliance believes that passwords are no longer as secure as they used to be. The days when only a few passwords were needed are over. Now there is a need for a password for absolutely everything. The risk is to forget the password, write it on a sheet (not very secure) or even put the same everywhere, on all sites. And there, all your accounts are compromised by cracking just one. The emergence of password managers, whether native to the device or not, helps protect your data. However, this is not always enough.
Fido stands for Fast IDentity Online. The objective of the Fido Alliance organization is to replace the password with 2-factor authentication. When connecting to a site with a trusted device, only another trusted device can validate this action. The only passwords you will need to remember are those to unlock your devices.
The most secure remaining biometric authentication (Face ID, Touch ID?).
With the arrival of Apple in their ranks, this will certainly speed up the process. Indeed, as you have certainly noticed, Apple already uses this double authentication system. With Fido, it would be possible to harmonize all devices without distinction of brands or operating systems. Indeed, not everyone is equipped with only one brand.
Connect to a site, without password, with your Windows and validate your connection with your iPhone, it may be possible one day.