Having a starting quarterback on a rookie contract is considered a gate key to success in today's NFL.
Ever since the Seattle Seahawks won Super Bowl XLVIII with Russell Wilson hitting the team’s salary cap that season for less than $1 million, NFL teams have sold out to this model of securing a young QB, taking advantage of his capped rookie salary and making a run at a Super Bowl during the window prior to the QB being due for major renegotiation.
Since then, the Philadelphia Eagles, Los Angeles Rams and Kansas City Chiefs (twice) all reached Super Bowls with their quarterbacks costing a relative pittance compared to the league average.