From 1994 to 1995 the league average pace dropped from 95 to 92 and hovered around 90 until '13-'14, where it's been gradually increasing[97.3 last year, 100 this year(last reached '88/89)]. This being caused by the highly controversial increase in 3 point attempts, going from 24% of total FGA in '13/14 to 33% in '17/18. However, teams aren't shooting any better from three(35%), than they were in 14'/15 or the past decade or two.

The league is playing at a higher pace, but unlike the 80s, it's not because the defense is absolute . Throughout the entire 80s, the league wide FG percentage was 49%(!!!), with a pace of around 100~. Compared to now where the league wide average is 45%, which is the average since forever.

Also for all the whining about FTs and flopping, FT/FGA are down from consistently being in the 24% range the last three decades to being 20% this decade.
It all fits together. More threes means less driving and fewer FTs.

Maintaining a 45% FG rate while increasing the number of threes attempted leads to greater offensive efficiency, and worse defensive efficiency along with it.

I don't know why the pace has suddenly jumped though. Last year the Pelicans led the league at 100.5, now the leage average is 101.6 (with the Hawks leading the way at a shocking 106.8). That's a serious e. The 14-second offensive rebound rule is the likely culprit, but did teams really used to milk the clock that much after an offensive rebound? I thought a lot of offensive rebounds led to quick shots.