The well worn line of "Dez isn't a great route runner" really doesn't add up. over 90% of plays call for Dez to run a deep post route.. when they do run him on slants and flares.. he has shown he can go up and contest the ball as well as any.
The problem with running deep routes on the current team is Dak doesn't have the arm to get the ball to him on the fly. I do not want to start a Dak fight but that is the truth. If you look at film, Dez does get seperation off the line but by the time the throw is made/ball travels to him.. the gap is closed and often the safety has come across in support. The adage of a QB throwing a guy open applies here too.
Dez could be a great WR and should be getting some big plays every game due to the line being stacked to stop zeke.. but his production isn't meeting his potential and I wouldn't be surprised if he looked for opportunities elsewhere.
Dak's big strength is protecting the ball.. he doesn't get turnovers because he rarely gambles (and that is just fine).. but Dez needs a gunslinger.. a guy that will give him that 50/50 chance to make the huge play. Right now they just don't suit each other or the play calling.