Half of what Faker does gets blown out of proportion, and he isn't nearly the god people make him out to be. Even just a simple juke or a flash is now considered to be a godly escape, when it concerns Faker. People, mostly analysts and casters, are believing in the hype and legend they themselves created.
Is he the best player in the world? Probably. People just forget that SKT also has 4 other world-class players on their team, that Faker can rely on. Something that isn't the case for most other teams, that have a weak link somewhere.
That said, opposing teams do often target him with either counter picks or jungle attention, making the laning phase more difficult for him. Therefore he can't snowball hard either. He still makes a ton of great plays in team fights though.
And it also seems that he didn't have a great tournament in general. He can't always perform at his best.