I'm not a huge Cousins guy and at his age, it might be time to move on. But your posts are just wrong. The Cousins we've had the last few years could have won a super bowl with the right coaching/supporting cast.
This idea that only franchise, gunslinging, improvising, walk-on-water QBs can win a Superbowl is just wrong. Rodgers, for all his talent, won one super bowl and is only 12-10 in the post-season, despite having a fantastic supporting cast and elite coaches. Matt Stafford won a Superbowl the year he lead the league in interceptions. Nick Foles won one. Case Keenan brought a team to the NFC Championship game. And Brock Purdy exists.
The legitimate concern about QBs is that they cost so much, compared to the rest of the team, that they can make building a roster very hard. I don't think the Vikings agree, but I think I'm ready to go with someone like McCarthy who seems to fit KOC's pocket passing model and use the savings to improve the team elsewhere.