A lot of this completion % stuff gets read the wrong way by the experts. If Allen threw 3 extra dump offs to RBs per game it would inflate his completion % and a lot of these experts would suddenly be making a big deal of his improvement, even though all he's done to improve it is throw 3 incredibly easy passes per game.
Now, that's not to say such throws are worthless because they can be the difference in moving the chains or punting, but it does show how such things an get overblown. it was the same thing when he left college. Everyone was making a big deal of the 58% (or whatever it was) completions and it just became this phrase everyone started parroting. One of the Josh Allen believers (might have even been Kiper) pointed out that he was making more difficult pass attempts because his team was so bad and needed to score, and that if he'd make a couple of easy check downs per game it would have inflated his % to 60%, in which case the stuff about his accuracy wouldn't have been talked about so much.