Ya I would say Phil Rivers is one. He has had a borderline hall of fame career of course, but not much success in terms of W-L/playoffs because his team around him could never take it to the next level.
(Got called out a few times on this post So to make it clear, I am referring to his overall team including defence, offensive line, special teams and coaching. Not just playmakers he had as he has had great players to throw to.)