Being the best player on the planet and failing to make a penalty kick when the finals depends on it is choking. Performing well below your usual levels in the biggest moments of the sport, when everyone is looking at you to deliver the goods - such as in the international finals - is a form of choking.
You cant be the greatest of all time and under perform in the finals again and again and again. You certainly can't be so weak as to miss a penalty kick to seal the deal and then "retire" (quit) to your country because you dont believe in yourself enough to get it done next time. I can guarantee that Maradona would not have quit on his country had he lost a finals on a penalty kick he botched. Messi is not as mentally strong as he is gifted. Compare him to Michael Jordan and the difference in intangibles, killer instinct and ruthless competitiveness are clear. Messi is gifted, but he is simply not a closer and not a killer out on that field.
Scoring penalty kicks is not a science, Vidal missed a penalty although he played superbly well during 120mn. He had Argentina's attack flowing during the game. Soccer is more than scoring goals.
Vidal doesnt matter, he's not even in the same league as Messi. To be the greatest you need to be a closer and show up on the biggest stages. Messi as the greatest in the world, the greatest on his team and some would argue the greatest of all time has a responsibility to close the deal. He failed. Pnalty kicks arent luck, if they were everyone would make and miss them at the same rate. They're equal part skill and ice cold veins. Messi is missing the latter and him quitting like he did proves that. Messi has a history of choking penalties away, just see chelsea in the finals. You cant make a claim to be the greatest of all time if you are unable to close the deal, again and again and again. In the NBA lergacies are made in the 4th quarter and what you do to close the game out. You need to close that deal in soccer too and it comes down to scoring a goal. If you're a forward and the game hinges on one goal difference, your job is to close that deal by scoring that goal. Not defer to someone else and hope they score it. You take it in to your own hands. See Zidan in CL finals, see Messi against Iran, see Maradona against England. The problem with Messi is that he has a history of being unable to step up and carry his international teams in big moments, where they are looking at him to finally close the deal.
Messi is top 5 all time, but I can't give him #1 just like I can't give Lebron James #1 in the NBA either - because both have a history of being unable to close in the biggest moments and stages of the game.