The team won 2 of 3 games without Kyler even on the field man.
Kyler had a passer rating of 67 vs Green Bay and the defense gave him the chance to drive down the field and win the game.
Kyler had 4 games with a passer rating below 90 and we lost all of them.
Stafford had 4 games with a passer rating below 90 and went 1-3.
Burrow had 4 games with a rating below 90 and lost 4.
Josh Allen had 8 below 90 and went 4-4 (but the 4 wins were Miami early when they were trash, Panthers with Cam at QB, Falcons and Jets)
Mahomes was 4-3 below 90 and the only real outlier of the bunch.
Seems pretty clear if your QB is below 90 you mostly lose, above 90 they mostly win.
This list of reasons is skewed to meet your narrative on first sight which isn't exactly accurate
1) I doubt McCoy wins one when the whole team started dumping a big stink, meaning we would have had more than one Carolina game
2) Which Kyler took and it was Green Bay which stopped that game winning drive. To say Kyler did not deliver is wrong
3) Stafford is Stafford and that is not unusual, because there were more than his share of games at Detroit where they lost because he did not have a over the top supporting class... hence, let's all stop making us think Stafford is some elite QB because the NFL likes the story, he's a vet and not a young guy like Kyler
4) Burrow is a young player and more apt to your poiny but is on a young team, and when the QB looks like crap after being great in other games, it's because other guys on the team are not giving any help
5) Allen plays amazing but has his share of inconsistency, sort of like past good/bad Wentz but those games are also blimps on their radar where the coach and other players did not show up... we cannot look at all these loses without putting the same critical approach on Kingbury taking for granted all these other coaches are always on point
6) The Chiefs have a lot of joker wilds in their deck and a crafty head coach, hence when the team plays well or rather has the potential to make big plays around their QB being off, you can win
7) Seems to me that when the whole team plays like crap around a good QB, there is a chance the QB will not play well and you lose... defense, offense around the QB, coach, injury situation, are just a few of the variables than just saying the QB in a vacuum is why you win
Kyler did not play well. That will affect the outcome in a major way but it's not just a QB playing by themselves to judge a team sport... goes both ways