You know what the 80's and today have in common with respect to PG height, a PG that was 6'10". It is not a coincidence that when Magic retired, the average heights of PG also took a nose dive. Similarly, there is a nice upward swing that starts when Ben Simmons entered the league and which dipped back down last year when he didn't play. Also not a coincidence that the center height went up with all of those super massive guys like Sampson, Bol, Bradley, Smits, Eaton, and into the 00's Ming and once those guys went away there was a bit of a dip, even still the average center is over 6'10" tall today. There is still a lot of size in the league, I mean the Cavs have 3 7 footers and a 6'11" guy all in their rotation. The Wolves are starting a 7'1" center and 6'11" PF (and probably a 6'9" SF). Memphis starting two 6'11" big men. The Bucks are starting a 7 foot center and a 6'11" PF. You can go on and on. The league isn't getting smaller, the style of play is just adjusting to less in the paint and more out of it.