I think Luck is underrated. Since day 1, he has played behind a terrible OL without much of a run game and only TY Hilton as a weapon. The Colts defense has also been terrible. It was all on his shoulders to put up big numbers or the colts lose and for a few years, he did. But he took a beating and it finally caught up with him.
And Chuck Pagano was a terrible coach. Frank Reich is the first real coach he's had aside from the year Arians was an interim.