It seems like the league changed the rules to favor passing, then all the teams loaded up to pass the ball, devalued the run game, but now the defenses have adjusted. 5 and 6 DB sets are the norm. Emphasis on pass rushing. I am not sure if the QB talent is any worse these days, maybe. It does seem to me that OLines are worse, or that there is less time that the pocket holds up. QBs seem to have no time to pass on all teams. Mobile QBs who can extend plays are having the most success.