That doesn't really prove anything because Dez was used as a chain mover more than most of those guys. Of WRs with at least 90 catches, Dez ranked 4th in YPC and 1st in first down %.
That's a sample of a grand total of 9 players you're talking about there. If you'd said "at least 85 catches," Dez drops to 9th in yards per catch, and 11th in yards per target. Out of 15 players (still less than half the starting #1 WR in the league).
Expand it to include the top 32 targeted WR and TE, and be done with it.
Yards per Target
Witten 14th
Bryant 17th
Yards per Catch
Witten 10th
Bryant 17th
20+ Yard Receptions
Witten 3rd
Bryant 17th
1st Down % per Target
Witten 14th
Bryant 12th
Success Rate*
Witten 11th
Bryant 19th
Pass Rating
Witten 9th
Bryant 11th
*percentage of targets that had a positiive effect on expected points. For example, it rewards 9-yard receptions on 1st down
as well as 3-yard receptions on 3rd and 2.
And these numbers aren't skewed by one player getting a disproportionate number of targets for his position. Dez ranked 6th in total targets among WR, and Witten ranked 3rd among TE. In fact, the high number of targets is what makes the pass ratings so valuable.