How do you replace over 1400 yards rushing and 560 receiving. Dallas had just over 5000 yards total offense in 2018. Zeke accounted for over 2000 of those.
DAK is the easiest replaceable, Pass Rushers are hard to find, Elite WR are hard to find, 2000yd RB's are hard to find, QB that are game managers are easier to replace. The Cowboys have elite players at RB, DL and WR. DAK is not in the Elite category.
It would be different if DAK was a Rodgers, Brees, Baker Mayfield, Sam Darnold type QB. DAK is a good/average QB that walked into an awesome situation in Dallas, and benefits from the Elite weapons on offense. Big difference