Especially in the age of rookie scale contracts in the NFL..
The one thing that gives credence to the idea that you've gotta win before you pay your quarterback is that, yeah, a small majority of teams that have won it all recently have done so while the quarterback was still on his rookie scale contract. Still, the Chiefs just won, and Mahomes got paid.
Sure, it's easier to staff your team if you're paying your quarterback like Brock Purdy than if you're paying DeShaun Watson.
Rebuilds are a thing.
Still, I think that a lot of the narrative around playoff windows can be chalked up to teams trying to hide mismanagement.
If teams really believed that the windows close once they pay their star quarterbacks, they wouldn't pay their quarterbacks. They would treat their quarterbacks the same way they treat their running backs -- use them until its time to pay them, and draft a new guy.
Acknowledging that teams can have off years, and years where they have to let go of valuable talent isn't the same as saying that the window closed. It's mostly that a lot of teams fail to make good decisions.
The Patriots kept a dynasty going with Tom Brady for twenty years. Of course, it helped that Brady was the GOAT, and never demanded to be paid like the GOAT, and had a running agreement with the team that he would take the pay cuts so long as they promised to spend the whole cap every year; but, that says a lot about Brady's personality. Isn't personality part of the hiring process?
The Browns aren't looking at going back to being the same old Browns because they paid a quarterback. They're going to go back to being the same old Browns because of gross mismanagement. They publicly scorned Baker Mayfield in order to give the most player friendly deal in NFL history to a dude who they knew was going to be suspended. The Watson deal is half the total value of Mahomes, and less than Josh Allen's or Jalen Hurts's; but, Mahomes, Allen, and Hurts are allowing their teams to spread it along a longer period of time. Allen has already taken a couple of restructures to open up cap space. The Browns structured Watson's contract to minimize his financial hit during his suspension. They paid him the league minimum in salary his first year, because the NFL can only penalize a players salary, not the bonuses. That means that the Bowns only paid out $1.6 million of his $230 million in the first year, and they're paying the rest now, and over the next few seasons. This is all for a dude with a questionable personality, who the fans don't want, who didn't want to play for the Browns but for the paycheck, and hadn't played football for a year prior to signing.
The Browns aren't seeing their window close. They're experiencing the consequences of their bad choices.
The Cowboys aren't seeing their window potentially closing because they paid Dak. Dak hasn't been on his rookie deal for years now. They're going to be between a rock and a hard place after this season because of mismanagement.
The Chiefs aren't going to have a closed window until Mahomes retires. The Bengals aren't going to have a completely closed window into Burrow retires. The Eagles aren't going to have a closed window until Hurts retires. The Bills aren't going to have a closed window until Allen retires.
All that's going to happen to these well-run teams is what will happen to the Eagles at the end of the Wentz era -- they'll have an off season or two before bouncing back.
Bad personalities and poor management closes windows, not paying a quarterback.