We could go back 2019, but then players who were in college skew the comparison; Tua, Joe, Jalen. Players in the nfl in 2019:
Kyler played a full season
Aaron played a full season
Lamar missed 1 game, MVP
Stafford missed 8 to get to 18
Daniel Jones missed 2 games
If we go back another year, Kyler and Dak’s closest injury buddy, Daniel, are not in the NFL. Stafford played a full season in 2018, as did Aaron, and Dak is still the clubhouse leader. At some point we’re comparing 25 yo Dak Prescott, and that doesn’t really prove whether or not a good backup is valuable as he gets further into his 30’s. We begin cherry picking the opposite direction.
2020 is 5 years ago and all QBs are active, it is the appropriate middle ground.