Manning came into the league in 1998. The massive shift of the NFL becoming a passing league happened around 2011, as evidenced by the 5,000 yard passers.
Peyton had Marshall Faulk and Edgerrin James from '98-'05. His career high in passing attempts was in 2010. Tom Brady's passing attempts jumped sharply in 2011 throughout the rest of his career.
Per Wikipedia:
"The 2011 season saw an unprecedented amount of passing offense: Three of the nine highest passing yardage totals of all time were established: No. 2 Drew Brees (5,476), No. 3 Tom Brady (5,235), and No. 9 Matthew Stafford (5,038); Eli Manning threw for 4,933 yards, which places him 14th all time.[1] It also saw Green Bay Packers quarterback Aaron Rodgers establish the all-time single-season best quarterback rating of 122.5.[2] Further cementing the modern NFL's reputation as a "passing league"[3][4][5] was the fact that, for the second consecutive year, the league overall set a record for most average passing yards per team per game, with 229.7, breaking 2010's record by more than eight yards per game.[6] (For comparison, the league-wide average rushing yards total finished the 2011 season at 57th all-time.)"
The defense rests.