Kurt Cousins should quite comfortably be seen as a top 10 QB in the league and I do think in the right situation he could win a Super Bowl.
https://www.statmuse.com/nfl/ask/who...e-last-3-years
His biggest issue is him and his coaching staff have probably played too safe come playoff time. It's a fine balance but you need to take a little risk offensively to win come playoff time.
Personally I think he's a lot better than Dak.