Sure an outstanding defense that creates turnovers and shuts down opposing offenses is preferred.
You can stockpile your team with 1st round defensive players.
Even a stub RB can be an asset and lessen the burden on the QB.
In playoff football, however defenses are good enough to shut down an offensive running attack.
Without a quality, smart, & physically gifted QB, your overall team will not even be competitive to make the playoffs, and eventually succeed in the post-season.
The 2015 Texans, the 2014 Jets, and the 2014 Bills for example all had outstanding defenses, but their QB play (Brian Hoyer), (Geno Smith/Mike VIck), (E.J. Manuel/Kyle Orton) doomed any team success.
In playoff football, it is the QB who completes passes and converts on 3rd down, throws touchdowns in the red zone, commits no turnovers (see Cam Newton in the Super Bowl 50, & Carson Palmer in the NFC championship game -- both failed to deliver and committed errors), & makes no dumb mistakes, that separates championship teams from other teams.
Some may say it is the defense that makes the QB look bad, but rather it is the smart QB who avoids the foolish & ill-advised gaffe when the game is on the line and the football is in his hands, that is the difference.
The Romo era is over.
It will always be a QB-driven league.
Go big or go home ~ draft Goff/Wentz.