The NFL has made it easier to pile up the passing yards. From protecting defenseless receivers to protecting the quarterback, professional football has installed a number of new regulations that have de-emphasized the running game and incentivized the passing game. What was once an eye-opening 3000+ passing yards type of league is not a ho-hum 4500+ passing yards type of league. And with a 17 game season for 2021, the lid may be taken off 5000 yards or even 6000 passing yards.
It may be wrong to look at two games and make projections for a 17 game season.