Argentina are not a great team in part because Messi has failed to make them a great team. That's his responsibility as the supposed best player of all-time. We're not talking about Messi transforming this team into the Dutch team of the 70s, we're just talking about him emulating Zidane in 2006, for example - creating a functional, if unspectacular, team with a standout player that can be relied upon to control the flow of the game against any team. Before Zidane came back into that team they were dysfunctional, disjointed, uninspired and lacking any kind of cohesion in midfield. That's more or less how Argentina have looked in at least 3/4 of their games with Messi in the team in the last two tournaments.
Argentina's defence (inc. Mascherano) has proven itself to be quite formidable over the last year or so with 8 clean sheets in 13 games in the World Cup and Copa America, so they've got a good base to work from there. It's not a star-studded defence by any means but they've worked quite well together. The problem is with their attack - they scored one goal or less in 9 of those 13 games. That's very, very poor. Messi as the chief playmaker and most prolific goalscorer naturally bears the majority of the responsibility for the cohesion, fluency and all-round threat of their attack and, given the talent he possesses, I don't think it's an exaggeration at all to say he's failed to live up to expectations. He was relatively good in both tournaments but far, far below his best - even if we just look at his time in the national shirt.
International success isn't the be all and end all but what Cruyff, Pelé, Platini, Maradona, Eusébio, Beckenbauer etc. did on the international stage which cemented their legacy was impose themselves on their national team in a way Messi or Ronaldo have never come close to. It wasn't their success that was so impressive, it was the fact that they were the quite clearly the key to making those teams tick, they created that cohesion, they were able to rise above the limitations of national football and create something beautiful. The excuses that get thrown out to defend Messi/Ronaldo and attack the credibility and value of international football are applicable to all of these players too.
The main explanation for Messi's failing is that he doesn't train with these players on a regular basis so how could he possibly hope to replicate anything like the kind of cohesiveness and fluidity in his play with a bunch of relative strangers. It's true, that's a significant challenge, but it's a challenge the vast majority of great players have been forced to (and been able to) overcome.
- In the 1986 World Cup final only three players from that Argentina team played together at the same club side - Pumpido, Ruggeri and Enrique. The other 9 players (incl. the one sub) played for 9 different teams. Argentina's attacking trio of Maradona (Napoli), Burruchaga (Nantes) and Valdano (Madrid) played in three different countries.
- This Argentina team in 2015 had four groups of players who played in the same team: Zabaleta, Demichelis and Aguero; Rojo and di María; Mascherano and Messi; Pastore and Lavezzi. All in all there were 9 different clubs represented in the Argentina team that played in the final yesterday (incl. the three subs) compared to 10 different clubs represented in the 1986 team (from a smaller squad).
That underlines the main point here about why international football is just as important as ever for judging the "greatness" of some players. The top players are all clustered together in a small group of elite clubs in a way they weren't in Maradona's time and previously, so the modern greats are afforded a tremendous luxury in the sense that they play in the kind of superclubs that just didn't exist in the past - or at least only existed once in a blue moon. International football however is much the same. The same challenges exist, the distribution of talent is the same, the format of the competitions are the same, the standard remains largely the same. It's easy to make direct comparisons between players in international football because it remains largely unchanged on all of those levels.
Messi has established that in a cohesive, fluid, attacking team filled with superstars he can rise above them all and stand out as a truly once in a generation kind of talent. That's proven beyond all doubt and it's a tremendous achievement that no-one will dispute. However to establish himself as something beyond that - to establish himself as the once in a century talent that people are talking about - then it's not unreasonable for people to think he needs to go outside of his comfort zone and establish himself once more, establish himself as being unparalleled no matter the circumstances or the environment he's playing in. Both of these two international tournaments have provided him with the perfect platform to do that and he just hasn't, and I personally think it's a tremendous shame.