Probably a number of economic factors. We see a corresponding bump in Bars and dips in College and Family, so I would guess there was an uptick in young adults going straight into the workforce due to compelling non-college opportunities, and then spending their hard earned wages on after work recreation. High inflation or overwork culture may have induced folks to spend more time at work or unwind more after work. Improvements toward gender equality in the workplace probably also contributed.

Whether any of that is accurate or not, I have no clue, but the dip corresponding to the 1990-91 recession leads me to believe the main driver for the 80s rise is economic.