Moss, Berger, Barichello, Webber... good enough to win races but not a championship.
Or is Rosberg like Prost or Senna, who stood out from behind a world champion (Prost with Lauda; Senna with Prost).

Rosberg has been in the game ten years; which is usually too late to win a first championship. Only Mansell, Andretti and Button have gone a decade before they did eventually win a world championship.
Time might have run out for Rosberg. He might have to shake his head harder to be rid of the No.2 hat.