The reason for this is simply to not continue building on a problematic foundation (cost of a quarterback makes it difficult to fill out the roster-more difficult depending on QB talent-it also ties your offense to a person for at least 3 years). I believe that it is better to boom or bust rather than tread water perpetually. If a quarterback is showing the excellent offensive output in the postseason-where points are scored on average without defensive turnover boosts (and taking standard deviation into account-not booming one game and laying an egg in another).
I studied a list of both AFC and NFC championship appearances all the way back to 1970 and found only a few guys that had started with a team and never left the franchise and then suddenly made the conference championship late in their career. Everyone of them was 60’s or 70’s era QB when there was no salary cap and they could be awful for 5-8 years but finally develop (they also got next to no pay which would have influenced their timeline). And even those had made a conference championship game by their seventh season starting.
Since this is Dak’s 9th season, he will need to break all time NFL history in making the conference title game this season with his original team. Here’s to hoping the defense can Dilfer us a SB. Keep opponents to 6 points or less (and ask Dak to please not gift any points away).