Could you elaborate a bit more? Saying he was bad imho is wrong, he was the best player at NT...he stole a lot of balls playing dmf even without being a destroyer and playing alone there just to make the balance in the midfield.
Also his passing was quite good, strong, looking for Messi and his distribution at his long balls was quite decent. I don't really know what you do expect from him but imho he had a good tournament.
Just to say, yes, you just watched the game vs Colombia and Argentina was a total mess...with a midfield without any kind of sense and Paredes very umconfortable with two very slow players near him.
When Scaloni played De Paul-Paredes-Acuña he improved a lot cause he was more covered and he had two fast players to accompany him and back behind the ball when the team lost the ball. Imho he had quite a good tournament and he claimed for a starter place at NT, one of the few.