I disagree with about every part of this.
Now, for the first time in quite a while, it doesn't "all come down to how good your QB is." Gardner Minshew, Mr. Irrelevant 2022, Geno Smith, Baker Mayfield, and Joe Freaking Flacco are all starting playoff games if the season ended today.
The 2021 team was loaded. What a bizarre retcon this is. We were 11th in points scored and points allowed. We had two pro bowlers on offense and defense. Byron Murphy had 12 passes defensed and four picks. Budda Baker had three INTs. We had two double-digit sack guys in Golden and Chandler Jones. The offensive weapons on that team included Hop, Christian Kirk, A.J. Green, and Zach Ertz.
Nice Cherry picking.
Gardner Minshew is a former starting QB, he's not even on a particularly great roster that's carrying him! They were 2-2 when he took over and 6-5 since.
Brock Purdy is a great QB that every team whiffed on. Like Tom Brady. I would swap Purdy for Kyler in a NY minute.
Geno Smith has played well and is under an all time great HC.
Baker Mayfield is 8-7 and just happens to be an an ass division.
The flip side of this is the Jets. A team everyone had down as SB contenders that might pick top 5 because they lost their QB.
The Falcons were pre season darlings and Arthur Smith was favorite for HC of the year, and have struggled because of QB play.
The Steelers, Packers, Broncos, Giants and Vikings have all underperformed their rosters due to QB play.
There's no single rule, it's some of both, but it's far more QB. QB is like 70% of the equation. A great QB will elevate average players and there is a long list of examples of this in the league.
Whereas you can have all the stars you like but if your QB is ass then you got nothing.