We don't need Varnish anymore, we have Nginx now. Does anyone here use Varnish because Nginx isn't good enough? If so, what is Varnish better at than Nginx, and

We don't need Varnish anymore, we have Nginx now. Does anyone here use Varnish because Nginx isn't good enough? If so, what is Varnish better at than Nginx, and by how much?