Most of this I cant really argue. We have absolutely zero evidence that Daks situation would change the player he is today, its 100% hypothetical.
The year prior to Dak coming on I get they wont four games, but that team had very high expectations prior to the Romo injury. I have 0 doubt that a rookie Dak was far superior to Cassell, Moore, and whoever ended up getting starts that year. It was a disaster of a season, but take away Rodgers from GB, Lamar from Baltimore, etc and these teams miss the playoffs as well.
Overall though I think the benefit is that this team wasn't a complete train wreck. For the argument of the Wentz/Dak debate I will concede that Wentz wasn't exactly in a bad spot either. Multiple pro bowl players on the O line, a dynamic TE, and a pretty strong defense. Receivers/RB were meh, but similar to what Dak was working with aside from Zeke. If we are going strictly on Dak vs Wentz, which I think is completely silly to do at this point I'm 100% on your side. I'm just looking bigger picture league wide as basically I think the Dak/Wentz comparison is laughable at this point.