Wild NFL Rushing Yardage Stat

There is a combination of factors at play. Off the top of my head - Defenses have adapted, many Hall of Fame level QBs were lost in a short timespan as well as many "Hall of Very Good" types, college football favoring more of the zone-read type offenses and stunting what was considered pro skill development, I also think we are seeing evidence that teams with great QBs are losing weapons quicker, partly because QB salaries have exploded so much, and lastly, there are several outright BAD QBs bringing the averages down.

The era where we were watching prolific guys like P. Manning, Brees, Brady, prime-Rodgers, Rivers, Big Ben, Eli, prime-Matt Ryan, etc. go toe-to-toe every week putting on pocket passing clinics are long gone. There was a time where it seemed like half of the weekly schedule each week featured some big time QB matchup, whether it was two HOFs battling or a couple of (legitimate) Pro Bowlers battling each other or the HOFers, and this just isn't the case anymore.