I don't agree with you, and I'm not pretending otherwise.
Eli was drafted in 2004, so essentially his entire career has been played with the new (anti-Ty Law) passing rules. Despite that, his career completion percentage is just 59.8% as of now, and his career QB rating is just 83.8. Just starting from there, we can see his HOF credentials, absent his two SB runs, are deficient. Then, you can add the following:
- In 14 NFL seasons, he's only gotten his team to the playoffs 5 times (he won't be making it this year).
- In his 5 playoff runs, he's either won the SB (2) or been one-and-done (3) (nothing wrong with the 2 SB wins, obviously, but being winless outside of that isn't impressive).
- His career interception percentage is just 52nd, despite being in this QB friendly era.
- His career yards per pass completion is just 134th.
- His career yards per pass attempt is just 82nd.
- Career winning percentage of %52.
- Realistically, his only impressive stats are the durability related stats. Those aren't bad stats to have, but they reflect time spent, not necessarily time spent as quality.
Or, since you brought up Flacco, to compare:
- Career completion percentage of 61.7%.
- Career QB rating is 83.8.
- 10 seasons, 6 trips to the playoffs, with #7 possible this year.
- In his 6 playoff runs, he's won the SB once, and has never gone one-and-done. He's 10-5 in the playoffs, which compares evenly with Eli's 8-4 record, despite the one fewer SB run.
- His career interception percentage is 16th.
- His career yards per pass completion is just 174th.
- His career yards per pass attempt is just 122nd.
- Career winning percentage of 60% (89-60).
In short, they're pretty much on the same level, though Manning's played longer. I'd give Manning the slight edge right now, if you took away the 3 SB winning runs from the pair of them, but the difference really isn't significant.