I think it's at least arguably true that Jund's card quality is not better than other decks. Every Bxx modrange player knows the feeling of Thoughtseizing that key card away, only for the opponent to topdeck another to make you waste your turn, or even lose on the spot. (Thoughtseize is itself a notoriously poor topdeck, of course.) Omnath, Teferi, Fury, end of step sweeper followed by two 4/4s; Jund has nothing like those. And, answers are always worse than threats when topdecking.

But for sure Jund is worse now than it once was due to the recent trend towards more draw-a-card or create-a-token text on all kinds of spells. Jund has some of those tools too, but the trend works against the hand-disruption plan.