1 or 2 years ago many rated him as the successor of Hummels and Boateng and the best german defender.
Last year he was injured almost the whole year and he isn't back to his best yet.
Personally I'm not his biggest fan. Physically he is very impressive, he is also quite fast for his size. But other than that he isn't that special in my opinion. Tackles on the ground and in the air are good but nothing spectacular, on the ball he is also okay but far from Hummels or Boateng on their day.
Don't get me wrong, he is a good defender, but not "best defender of Bayern/Germany" level in my opinion.