He deserves next season with a top rated QB right next to him. The problem I see with Dak is his anticipation. He has no anticipation and trust for his QB skills and he'd better learn it quickly before the 2018 season. When a guy is running a route, you have to anticipate him being where he needs to be and let it fly before he gets there. He has to trust this part of QBing and he doesn't.
This is what they mean when they say, throw a WR open. There was a crossing route I saw that had a receiver crossing the middle with two LBS shallow, he held up the ball because he didn't trust himself to get it over those LBs and before the receivers hit the second array of safeties, so he tucked it, tried to run but all areas were closed so he tossed it out to Zeke (over thrown) pick 6. But your coaches have to coach that into him, throw it before anyone can react. If you're a coach, you have to coach. If they are coaching him to do these things yet he just can't do it, then it's time to move on from him.