I can understand that, and a user can also enjoy the simplicity of the process. However, I’m speaking about this very popup here. It doesn’t have to be this way. There are plenty of websites that allow you to sign in/up with Google (or another 3rd-party provider) that don’t have this problem. I see so many websites and mobile apps that make it very difficult to use them. I always wonder if anyone at the company is using their own website/app. Reddit is another great example.