This article notes the offensive woes should not all be laid at Dak Prescott's feet. Janoris Jenkins effectively took Dez Bryant out of the game on Sunday, and the Cowboys never properly adjusted.
Jenkins has especially been impressive against Dez Bryant this year. In two games this year against the Cowboys, Bryant has caught 2-of-14 passes for 14 yards, with a key fumble that helped seal this game.
The problem for the Cowboys if an opponent can seal up Bryant is that, while they have decent receivers, they don't have anyone else who can win one-on-one at ease.