His biggest strength is Calabria's weakest. (one on one defending)
His weaknesses are Calabria's strengths. (technique and endurance)
This is a myth. Calabria is a fantastic one on one defender. He always racks up ridiculous numbers of tackles and generally leads the team in tackles completed, some of his best games in recent years Calabria had had around 10 tackles in one game which is just crazy.
Calabria is weak with his positioning though, and to be fair to abate, he is a good one on one defender as well. Calabria finds himself out of position on occasion or he has been prone to give the ball away in dangerous areas. We've definitely all seen Calabria lose his man and be trailing the play, but statistically, he could be the best tackler on the entire team. Don't care about the perception of Calabria either if people disagree, it's a fact and has been for years