You word this as though most QBs can play 4 straight games of something called good clean football. And that it is predictable.
Further, I imagine your definition of good clean football is quite different than mine. And I also imagine it is different from week to week and team to team.
So, now that you've thrown down the gauntlet, define precisely what good clean football is. Does it apply to all QBs or just to Stafford? And apparently, conditions and circumstances are completely independent of whatever your definition is. Right? Covid doesn't matter. Injuries don't matter. Weather doesn't matter. Traveling or home doesn't matter. Opponent doesn't matter.
In fact, your premise that one subpar performance and the season is over is completely disproven by the previous game against Minny. A QB in the playoffs can of course have a "subpar performance" (whatever the heck that is) and the team still win. Why? Because football is a game of 11 against 11. Not QB against QB.