This is as good as it will ever get from Dak. Experience won't really make him a better QB - he is already in his 6th year and I just don't think there is an extra level that he can get to. He knows how to recognize blitzes and can beat them, which is a skill that a starting QB should have. But there are probably 15-20 QBs who can do that too. Once defenses start disguising coverages and looks, they know Dak can't beat them.
So congrats to Dak, he's aced Basic and Intermediate NFL QB-ing...many NFL QBs in the history of the league can't make it past one or both. But Advanced NFL QB-ing is a level that only the truly elite at the position can get to and for a lot of guys, it is simply unreachable due to physical/mental limitations (or a combo of both)