And I disagree with this. Ben was certainly diminished at 39 years old but he orchestrated 6 or 7 4th quarter comebacks this year.. using this metric you can extrapolate the Steelers would have only won 2 or 3 games.
They were coming back from his play in the first 3 quarters. Its not like the defense was the reason comebacks were needed. The Steelers had 1 win this season in a game the defense gave up over 20 points, and that was the Monday Night game against Chicago, which was a game the Steelers never trailed in until the final 2 minutes.
Taking it game by game:
Week 1 Buffalo=Ben didn't do anything to lose the game, but the defense holding the mighty Bills offense to 16 is why they won.
Week 2 Las Vegas=Ben was ok, but didn't make any real plays, and only scored 17 in a loss against a pretty mediocre defense.
Week 3 Cincy=Ben was bad, and only led the team to 10 points. There was no Diontae Johnson that week, but 10 points is still unacceptable.
Week 4 Green Bay=Ben was bad, and that was with Johnson back, and despite the defense doing a pretty good job against a top offense.
Week 5 Denver=Ben played well in a win.
Week 6 Seattle=Ben was ok, but didn't really do much in an OT win over a Wilson-less Seahawks.
Week 8 Cleveland=Ben didn't do anything to lose the game, in a 15-10 win over the Browns, in which the defense played great.
Week 9 Chicago=Probably Ben's best game of the season, though a game most would argue was decided by a horrible penalty call.
Week 10 Detroit=Rudolph started, and played poorly. The run defense was the biggest problem for the Steelers this week though, giving up 229 yards, including several 20+ yard runs. Also, soft fumbles from Diontae and Freiermuth. Honestly, kinda lucky this ended up being a tie.
Week 11 Chargers=Ben did nothing for 3 quarters, before making a game of it in the 4th. That said, I'd put this loss more on the defense, as they had no answers for the Chargers offense.
Week 12 Cincy=The worst game by any QB so far. Ben was awful here. 3 turnovers, including a pick-6. Only 3 points until a garbage TD with 3 minutes left. The defense wasn't good in this game either, letting Mixon go for 32-163-2 in total.
Week 13 Baltimore=A mistake free game from Ben, albeit one against a secondary that was running out of bodies. Great game by the defense, sacking Jackson 7 times.
Week 14 Minnesota=Another garbage time special for Ben, as the offense was shut out until almost the 4th quarter. The defense got gashed by Davin Cook in the 1st half, but played much better in the 2nd half, including picking off Cousins twice to make it appear close.
Week 15 Tennessee=Ben didn't lose this game, as the defense carried the Steelers to a 19-13 win. 4 forced turnovers for the defense was what won this game.
Week 16 Kansas City=The defense got destroyed here, but again 0 points until almost the 4th quarter. Ben was terrible in this game, and was rightfully pulled late.
Week 17 Cleveland=Pathetic game from Ben. 123 yards on 46 attempts. This was the definition of winning in spite of your QB. Huge game from Najee(arguably his best) and a great defensive effort with 9 sacks and 2 INT's.
Week 18 Baltimore=Ben didn't play well here either. Carried to a 16-13 OT win on the back of 3 Tyler Huntley turnovers.
Wild Card Kansas City=A fitting end to the season, getting shut out until almost the 4th quarter. 2 garbage time TDs make his stat line look ok, but there was zero offense until then.
All in all, I see a QB who rarely played well, and usually was below average or worse. As much crap as Rudolph gets I doubt he'd have been worse. Ben's 2021 and Rudolph's 2019 are actually very similar. The biggest difference is Ben had a much better skill position supporting cast in 2021, and Rudolph had a better OL in 2019.
My biggest takeaway is that Mike Tomlin deserves all the credit on the world for getting this team into the playoffs. The defense carried this team all season, and pretty much any time the defense wasn't great, was a loss. I don't think it'll be difficult to replace Big Ben, it might be difficult to get worse. That said, its probably asking a lot for the defense to stay at this level as well, so the Steelers will likely need better QB play next year, just to make it back to the wildcard round again.