Dynasty Age Peaks and Cliffs for Each Position

Below are the reference articles you can read through, but I will give you the TLDR here.

RBs

Peak RB age: 23 to 26 years old

Since 2010, 90%+ of fantasy seasons with 250+ PPR fantasy points happened before age 29 season. Most common ages were 24 and 25 years old.

Fall off RB age: After age 28 season

Carry threshold: After 1500 carries, we tend to see a sharp decline independent of age (Josh Jacobs is 26, yet has 1300 carries to his name. Had light usage in college, though)

WRs

Peak WR age: 25 to 30. Elite WRs can go a little further, to around age 32. Average age of elite WR performances is around 27 years old.

Fall off WR age: After 30 for non-elite, 32 for elite

TEs

Peak TE age: 25 to 27 years old

Fall off TE age: After 31 years old

https://www.espn.com/fantasy/football/story/_/id/37933720/2023-fantasy-football-players-peak-decline-quarterback-running-back-wide-receiver

https://apexfantasyleagues.com/peak-age-nfl-running-back/

https://www.fantasypros.com/2021/07/at-what-age-do-running-backs-decline-2021-fantasy-football/

https://www.thefantasyfootballers.com/articles/the-lifecycle-of-a-dynasty-running-back-fantasy-football/

https://www.fantasylife.com/articles/redraft/fantasy-football-age-cliffs-and-takeaways-for-every-position

https://www.pff.com/news/nfl-breaking-down-fact-and-fiction-about-how-and-when-nfl-running-backs-begin-to-regress-2021

https://www.fantasypros.com/2021/07/at-what-age-do-wide-receivers-decline-2021-fantasy-football/

https://apexfantasyleagues.com/peak-age-nfl-tight-end/