I think you are subscribing to two false premises:
False Premise 1: Elite athletes age more poorly than non- elite athletes who do not rely on athleticism. This is simply not true. Jayden Daniels can lose a speed and still have above average athleticism. They can learn the game better over time. Margin athletes who lose a step are out of the league. The two elite athletes at the QB position - Michael Vick and Randall Cunningham both had very successful seasons at 30 or older.
I didn't say they age more poorly. I said their career peaks are shorter because they rely on athleticism which declines with age (and injury). Cunningham is a great example in my favor. After his age 29 year, he was pretty much done as a running QB. Age 30 onward, here are the number of games he started: 4, 14, 4, 3, 14, 6, 3, 2. He had just *one* great season after age 29, when he was 35.
Do you still take Daniels if he follows a similar trajectory? And will you bank on an unproven ability to be an elite pocket passer, when he hasn't played without that extraordinary athleticism his whole life? If he had a bigger body, was succeeding without elite receivers, and could throw over the middle, I'd take him for sure, but then he wouldn't be there at 3.
Daniels isn't even in the same solar system as Vick for athleticism. But even so, Vick was done as a major force after his age 32 season, despite sitting out the majority of 3 seasons for being a monster.
False Premise 2: You somehow seem to be very worried about an extended career. Any QB that makes it to contract 2 with the same team is a win. Joe Burtow came out at 23. Four years into his career, like almost all successful quarterbacks, he signed a 5 year extension. That is the standard. No one is worried that he is under contract until 32. If Jayden Daniels is good, no one will care about a 5 year contract at 27-28. They will care if he stinks and doesn’t deserve a second contract.
Contracts? I'm unclear what point you are trying to make. I'm not worried about an "extended career", I'm worried about Daniels being done (or incapable of transforming his game to adjust) at age 28 after building an entire offense around him, and then the Pats have to start all over again. If you have a franchise QB, you'd like to keep him for as long as you can, right? They are tough to come by. Since 1970, the Pats have only had Bledsoe and Brady.