I think the issue with Dak being a "running QB" is that instead of making him learn to sit in the pocket and learn to read defenses and master his footwork , you are basically giving up and saying that he will never learn.
As time goes by , his athleticism will deteriorate and you will be left with an unathletic QB that can't sit in the pocket.
Think of Dez Bryant and how once his athleticism left him he was done because he never learned the position.
Older QBs all stick around because of their mastery of the position.
If Dak doesn't learn how to be a pocket QB now , when will he?
Gimmick QBs don't amount to much.
The greatest QB to ever play the game (Brady) is a lanky , slow , statue... let that sink in.
Why can't defenses stop him or figure him out after 20 years in the league?
You make some good points, but Brady started out as a bus driver qb.
He just played smart limited turnovers and mistakes, and the pats defense was very good at that time.
Plus he has the best HC in the league.
Brady worked hard to get better and know the game better and both he and bill just keep adapting, and adjusting.
If teams figure them out they adjust and adapt.
Every qb in the league is different and they are on different teams with different coaches, and players.
Dak happens to be on a weird team with a HC in training and meddlesome owner gm's and right now not a good supporting
cast on offense as far as being a passing qb.
Can Dak last a long time as a running qb? no maybe 4 more years if he is smart when he runs.
Dak is very stoutly built so if he runs safe he might last a good while.
I dont think as a runner he is a gimmick qb, I dont think there is such a thing.
getting better as a passer he needs to keep working on that himself and find someone who can teach him some things.
But for the present there is nothing wrong with him running .
Russell Wilson won a SB as pretty much the same type running qb.