Majority of his chances are crosses, this is not his fault, he is just this type of player.
However it’s quite clear even in YouTube the German back lines are often not there because of how they launch the counter, or they simply don’t position many players inside the box to defend against Hertha. This is extremely important for a wing player, because as we know, 80% of the teams in the league actually sit back against us. Due to the distance of a cross can go before it reaches our players, coupled with the number of players inside the box ratio is greatly in their favour, this is why we have been the team with the greatest number of crosses but barely any of them reach its target.
This is why players like Perisic and Candreva, who outside of the club or before joining the club, were considered great crossers, but turned into chumps with us, due to their one dimensionality in their play plus their cross. (Perisic is better in this regard as he scores and defends also, but Candreva's only throughput was crossing).
This kind of stats is pretty much a total bias towards their clubs and league, and is probably not transitive, at least easily, to the Serie A.
Of course, there are other things to like about him, but just be careful with these data. They are only a representation in his current environment, not a prediction and definitely not a guarantee for anything in the future.