-You cannot just go by stats alone. The offense wasn't as good as the stats stated nor the defense was as good, either.
-There is a reason why our new HC MM stated that he will only be tweaking the offense, where they want to overhaul both the defense and special team units.
-Dak and the offense was forced to drive the entire field on a given basis as the special teams unit was one of the league worst and a defensive that simply couldn't generate a turnover to save their lives. They had 7 interceptions for the entire year! The Cowboys were #2 in the entire league of average yards per drive. This suggests, poor starting field position.
-The offense struggled at times to finish off long drives, usually self-inflicted penalties. Their PK missed makeable kicks on a consistent basis that netted out zero points, changed momentum and gave the opponent great starting field position. Opposing teams needed less yards to score points, hence helped the defensive stats out.
-We did see the Cowboy Defense struggle against average QB's all season long. Hell, Miami even gave them serious trouble in the first half. The Jet game comes to mind, the offense driven the football the entire field, Garrett refused to take the 3 and they were turnover on downs inside the Jets 5 yard line. Darnold then hits the defense for a over 90 yard TD, that's unacceptable especially when he missed the 6 games prior. That same game both our tackles were out, Cooper left in the 1Q and Cobb didn't dress due to injury. Did the defense help them out? There were several others like this game. Outside of the Saint game, the defense was piss poor for the majority of the season.
-Defense wins championships, it's the reason why the Cowboys haven't gotten past the divisional round of the playoffs.