Feel like this is a bit of a stretch considering 3 of the wins you’re listing are by Andy Dalton who was named the starter in 2021. I wouldn’t count him as a true backup - he was legit better than Rookie Fields.
In 2022-2023, it would be 2-4 vs 4-17; still awful but doesn’t show that the backups are winning much more.
Agree with everyone else but I also think a change of scenery and exposure to other plays helped his development. Theres a reason why we think of certain players like Drew Brees as a Saint but he actually started by the Chargers and played four years there.
I don’t follow him enough to know but I see online he’s listed as a defensive end so he may be playing more to his fit schematically as well.