These are some low standards for greatness. He played 70 minutes of the world cup.
At Bayern a great 27 year old player doesn't get loaned out. He showed great promise, but not performances. Bayern needs to replace the ancient Robben and Ribery and yet they sold their young winger in his prime, because he failed to meet expectations.
Same with Juve, we saw a great few months and that's it so far. First half of last season? not much. This season? nothing. He can't be a great player for Juve if he only delivered some 5 months of performances.
At Shaktar sure, I don't know. I guess yes but only saw them in CL, not in Ukraine. Problem is that the Ukranian league is a drastically lower level than we need.
He is useful, but has many limits.