There is no reason to believe that they will not improve with more time, and more time together.
We have a solid core, and a competent coaching staff.
Yes, I know Dallas went 13-3 last year and missed the playoffs this year, but Jason Garrett (aka The Clapper) is their head coach.
We are a young team, and, it turns out, maybe playoff experience does count in the end. i think the team played tight, McVay coached tight. But they will learn and improve. Remember, statistically Goff was the worst QB in the league last year. He has lots of ceiling yet to reach.