You can also argue this same point from a security standpoint. Having a single centralized authentication that users must always sign in to and they are never r

You can also argue this same point from a security standpoint. Having a single centralized authentication that users must always sign in to and they are never required to sign in elsewhere will make users more aware of any phishing attempts. If a user suddenly sees a prompt in a different location or from a different service for their credentials they are less likely to just provide the credentials there and question it's authenticity.