You may be right, but I don't think so. A run-first team can be hard on some QB's. Some QB's need a lot of pass attempts to get into a rhythm. It's hard, for many QB's, to consistently pass the ball accurately and effectively if they're only throwing it 20x a game. It's like, alright, I know you've only thrown the ball 1-2x in the last 10 plays, but we need a big 3rd and 8 conversion now. It's not that easy IMO. Big time passing QB's need to pass the ball, they want to pass the ball. So in this offense, we would go away from what makes it great: running the ball, and running it a lot. The dynamics of the passing game would change, and that may be fine, or it may not.
To me it comes down to this: This offense works. It scores points, and it scores a lot. TD's/play; Red Zone offense; total points; Touchdowns scored (not fg's); 3rd down % it's 14th, not great but not horrible. TT has been a part of that. It can't be denied or taken away from him. Pick up the option, pick up a better RT, and add WR depth.