He isn't a pure #9 though is he? A pure #9 is someone like Higuain, Giroud, Gomez, Aduriz or Klose and he has FAR more to his game even at this advanced stage of his career than any of those players have ever had. Even in a declined state, he offers more to his team than most players and more than what people on this forum are giving him credit for. Even the supposed tap-ins and penalties he always scores is somehwat exaggerated and you only need to watch his top 10 goals in la liga alone this season to see this. So much variety in the goals.
And yes portugal's success was mostly due to their defensive approach but to say that he "he was far from the most decisive player for Portugal" is nonsensical as he literally saved them from elimination in the last group game with 2 goals and an assist in a 3-3 draw with Hungary whilst in the next round against Croatia was involved in the game winning goal. In addition to that, he acted as a great leader and put confidence in his teammates against Poland in the crucial penalty shoot-out and even went first and scored. Not to mention, he scored the opening goal in the semis and inadvertently assisted Nani for the 2nd to seal the game. Yes, I agree Pepe was overall the best player but that's a lot for someone who was "far from being decisive."
Messi and Argentina had a much easier route to the copa america final (even playing less games): facing minnows such as Panama and Bolivia in the group stage and Venezuela and USA in the KO rounds before meeting Chile in the final.
Virtually, every team CR and Portugal faced in the KO rounds were considerably stronger than any team Argentina played in the copa america barring Chile and this is with Portugal having a less talented team.