Dak can't make throws if he gets pressure 80% of the time, no quarterback can. You begin to hear footsteps, don't care who you are. Eli's the classic example - he's won 2 SBs, but knock him around a few times and he turns into a poor quarterback.
Other teams, like Seattle, when they have problems in pass protection or whatever, make changes and fix the problem.
This team can't.
I don't blame Dak, Zeke, Sean Lee or any other player. They play the best they can. Every player has faults and weak areas in their game. Good coaches put them in positions where they can utilize their talents.
This coaching staff, from Garrett on down, haven't a clue how to do that.
Oh wait, I except the kicking coach, he does a good job...