Almost exactly two-thirds of all offensive yards gained in 2020 were passing yards. This was actually down a bit from a high of 69.1 percent in 2015. Back in 1977 more than half of all offensive yards were rushing yards. Also back in 1977, 5.23 percent of all passes were intercepted. The percentage of throws intercepted in 2020 was the lowest that it has ever been - 2.06 percent.
This means that the league as a whole has gotten much much better at passing the ball since the early years after the merger.
Back in 1988 the average team passer rating in the NFL was 72.