Microsoft
MicrosoftEd_Eastman This is still 2 factor authentication. With Windows Hello, it uses the combination of the device as one factor (something you have) and a PIN (something you know) or biometric identifier (something you are) for the second factor.
It’s also not a single login for every service in the way you’re thinking. With FIDO2 your identity for each service is securely stored in a device, such as a USB key, PC, or phone. When that service requests your identity for authentication, the device can see which service is making the request and use the matching identity to respond and complete the authentication. It might seem like it’s all using your windows login for every service, but in reality that is just windows verifying your identity in order to allow you access to those securely stored credentials for Google or whatever. It’s like a password wallet, but better because it stores cryptographic credentials instead of a simple password.
