Wait, what? Deion Branch's numbers in Seattle were almost the same as they were in New England, unless you're completely ignoring his injuries. He was hurt the 1st 2 games of 2016, his first season there, worked his way back, and finished as the 2nd leading receiver on a team that won the wild card game, and lost in the divisional round.
In year 2, he missed the middle quarter of the season with an injury.
In year 3, he missed half the season. But in Seattle, his per game numbers were roughly on par with what they were in New England.
You think Philly's O line play has been bad this year, because Hurts has been sacked 34 times? When Hurts gets sacked, we blame his O Line, but when Mac gets sacked, well, you blame Mac. Give me a break, Miles Sanders is ALREADY over 1,000 yards rushing this year on 5.2ypc. AJ Brown is already over 1,000 yards receiving, and Smith will get there too barring injury. Almost every single cite from PFF to Profootballnetwork has the Eagles offensive line ranked #1 in the NFL. What are we talking about? Hurts has a great offensive line, and arguably one of the best skill position groupings in the NFL when you factor in WR/RB/TE.
Tua had Waddle, a rookie, in 2021. And Tua put up the same type of numbers that Mac is putting up this year. What changed in Miami? The skill position players got better, they went and spent a ton of money on Armstead and Connor Williams and shored up their offensive line. Oh yeah, and a new coaching staff.
Ironically? It's not ironic, it's pretty straightforward that Allen improved dramatically in large part because they went and got him Diggs. In 46 games since he's been there, Diggs has 463 targets. If Allen was sending those 463 passes to say, Davante Parker and Jakobi Meyers, do you think he's anywhere close to the same numbers?
The reason those guys showed improvement from year 1 to year 2 is because they all FUCKING SUCKED COMPLETE ASS AS ROOKIES, unlike Mac, right? Their 2nd years weren't even as good as Mac's rookie year, and are basiclally comparable to Mac's 2nd year.
Rookie years:
Mac: 67.6%, 22tds, 13int, 223.6ypg, 92.5 rating.
Allen: 52.8%, 10tds, 12int, 172.8ypg, 67.9 rating
Tua: 64.1%, 11tds, 5 ints, 181.4ypg, 87.1 rating
Hurts: (didn't start much), 52.0%, 6td, 4int, 70.7 ypg, 77.6 rating
These guys, other than Mac, had nowhere to go but up in year 2. And even then, they basically put up the same numbers as Mac is putting up this year in his 2nd year. You want Mac to improve from his rookie year, which was substantially better than any of them, even though Mac has a much worse situation around him now on O Line, coaching and skill players (due to injuries) than he did as a rookie.
Deion Branch's catch% and YPT take a direct hit when going to Seattle, they rebound briefly, possibly due to small sample size due to the injuries, but then spike when he returns to the patriots. I don't think this is entirely on Deion, considering the drop in QB ability; though perhaps a better WR would have less of a steep drop.
Regarding the Eagles, the alternative non-mutually exclusive explanation is that Hurts is improving as an NFL QB. You're right that sacks alone don't determine OL play, its hard to separate OL from QB play; and both can influence one another for all sorts of reasons. Of course the pressure numbers stand in contrast to the ratings -- which themselves may be biased by how well the surrounding cast plays -- certainly having a loaded skillset makes it harder to pressure the QB or force tight throws. However, the skillset players Hurts has have been largely intact aside from AJ Brown. RB is largely unchanged since Hurts first signed -- Sanders was at 5.3 in 2020 and even better efficiency 2021, though limited in action. TE/OL hasn't changed since 2021; the distinction has been volume and some of that has been helped with Hurts playing better and sustaining drives -- dramatically reducing mistakes and turnovers -- leading to more play calling. AJ Brown certainly accounts for some of that, but simply getting top-tier WRs doesn't make a QB excellent (e.g. Alex Smith).
As for Tua, he's been pressured about the same this year as last year -- so whether that money made any improvement for his passing game is questionable -- what has changed -- like with Hurts -- is that Tua cut down on his mistakes. Coaching staff may have helped with that, or Tua might've improved on his own -- or more likely its a combination of both.
Allen has been *worse* in the last two seasons as Diggs has settled in -- in fact in 2021 he wasn't much different from Mac in terms of overall performance; actually, all of the QBs you mention perform pretty similarly in their 2nd year to Mac's rookie year; Tua would be weakest and most comparable to Mac's current season (though still noticeably better) due to more mistakes and lower Y/A. Mac's rookie year is good for a rookie largely because rookies playing tends to be rare in the league; the hope is that this establishes the floor. I've reposted them from your post for below, even though these are terrible numbers to use for comparative purposes (TD%, int%, ANY/A would be better replacements; or even AY/A if you don't like sacks).
Hurts: 61.3%, 16td's, 9 ints, 87.2 rating, 6.38 ANY/A, 209 ypg, 15 GS
Allen: 58.8%, 20td, 9ints, 85.3 rating, 6.35 ANY/A, 259 ypg, 17 GS
Tua: 67.8%, 16td, 10int, 90.1 rating, 5.81 ANY/A 204 ypg, 13 G/12 GS
Mac: 67.6%, 22tds, 13int, 92.5 rating. 6.22 ANY/A 223 ypg 17 GS
I disagree with the bolded, as the disparity in TDs between the QBs 2nd years is huge. Here's Mac's 2nd season reposted:
Mac this season: 68.2%,
7td, 8int, 85.7 rating, 5.45 ANY/A, 219 ypg, 10 GS
Mac had a phenomenal year for a rookie -- most rookies don't perform that well as we praise one of the best rookie QB seasons despite it being comparable to a mediocre 2nd season QB performance; in terms of the overall NFL it was average -- had he maintained a similar performance year this year, despite circumstances beyond his control like limited OL depth, that would be one thing. However, its clear that his floor is much lower. He's played poorly for most of the season. In fact, Mac was playing poorly before the O-line degraded and the ensuing sacks -- most of his picks came prior to the sack barrage, and were against medicore defenses like Baltimore or Miami. He's actually looked better in recent weeks, especially when weak defenses like the Vikings do not pressure him -- and therefore remove the weak OL play from the equation ( he struggled when MN was blitzing in the second half, but again the OL was weak at that point).
Lately, he's largely avoided mistakes, improving his footwoork, and he showed some ability for the deep ball i.e. on those deep routes to Henry; but his awareness particularly in clock management seems questionable. This is despite absences to the passing/running game in Harris/Rham/Meyers. It would be nice to see if any of it is sustainable; such improvements may pay off with a revamped OL and revamped coaching, but taken in aggregate. Mac's floor is pretty low and he's shown limited physical tools that suggest his ceiling is high; there's little reason to feel confident about paying market prices for Mac after his contract expires.
Interconnectedness is a two-way street, and simply blaming the OL and coaching staff alone isn't enough -- the problem with QB is that one should not expect a rookie, with small exceptions, to step in, so the planning for drafting a QB should be longer. As of now, we don't have a QB that's worth contention for starting in 2024 (Mac's final year); so QB needs to be a point of consideration alongside the OL. Frankly, I trust BB to draft a QB far more than a WR, given his history with the former vs. the latter.