Yeah there's the James and Cavani injuries (especially tough for Uruguay, who are dependent on four individuals + order and grit, and Cavani was their best player this tournament), and also three South American teams were essentially eliminated by the same team -- France, arguably the most solid team in the tournament, eliminated Peru, Argentina, and Uruguay one after the other.
Then there's the fact that Colombia lost in penalties, Brazil was extremely unlucky. Peru was always going to be a long shot as first-timers for that generation, and it was a tough group comparatively. And Argentina was pure shit. Still, they all gave everyone a strong fight, none went out easily.
Nothing to complain, all teams went out fairly, but mostly because of small details, bad luck, etc.
Not to mention, in Brazil 2014 several South American teams were eliminated by other South American teams.
So obviously European national teams are doing better, but some context shows it's not such a big difference.
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