Dak gets no help from his coaches.
Mahomes is great. But he is helped greatly by Andy Reid's offense and his schemes to get receivers wide open. He rarely has to throw into tight windows. There are always receivers running wide open. This is Andy Reid and his modern offense at work.
This offense is the exact opposite of that. And you are asking a QB much less talented than Mahomes to throw darts into microscopic windows. Garrett and Linehan have no clue how to scheme receivers open. Their "just beat the guy in front of you" offense is killing Dak.
We are seeing the results of that.