Manning's a bad comparison for nearly everyone—even Pro Bowlers—because anomalous: He's a first ballot HoFer STILL at the top of his game after 15 seasons. Decker won't be playing at 38, much less playing WELL. The average NFL career's 5 years, and the window between rookie "take it or leave it" deals and vet "over-the-hill, one injury from retirement" deals is narrow even for the best: That's the brief span when they can command the long lucrative contracts that make them independently wealthy for life, so the smart ones take it while they can. I can't blame Decker doing so.
There've been many retired HoFes living in luxuy who'd trade some of that wealth for just ONE SB Ring—but probably at least as many who had to pawn SB Rings to buy the car they live in, or surgeries and other medical care football made a part of their lives for however long they still have one. Jets fans should be grateful for one of the few bright spots on a team that's been an embarrassment ever since Namaths knees went.