Djokovic struggled against Wawrinka in AO 2013, actually lost to him in AO 2014, RG 2015, USO 2016...Was he terrible at all these slams?2013 was a patchy year by Djokovic, the USO final was sort of the tipping point before the Becker involvement IIRC. If you look at the last three rounds of the USO he struggled with old man Youzhny and Wawrinka, he didn't play well in either win. Then in the final he started off badly and ended badly. Where as 2010 was a poor year pretty much the whole way through but the USO run was the highlight where he actually acquited himself pretty well in the final - it didn't have the highs of the middle sets of the 2013 final but it didn't have the valleys either.
And I don't think the USO final was an outlier at all, he was poor in the Wimbledon final and had underperformed in pretty much all the masters apart from Canada and Monte Carlo.
What Nadal did in Montreal, Cincinnati and USO 2013 was an amazing achievement, doesn't matter how much some users here are trying to bring it down. In the middle of the second set of the USO final Djokovic started GOATing, at the beginning of the third it looked like the match was over. Nadal somehow managed to level the score, but soon enough found himself at 4-4 0-40 on serve. He saved the first BP with a great winner, survived a long rally on the second, hit an ace on the third. Not a choke from Djokovic by any means. In the next game Nadal broke from 30-0 down. On 2 points Djokovic hit errors but the other 2 were won by Nadal himself with some very clutch play. Then he began the fourth set by saving a few more break points...Wait, why am I writing all this? Djokovic was terrible during the whole match, end of story. Nadal doesn't deserve any credit.