I don't know, but sitcoms moved from "just hanging" to a more aggressive approach to comedy in the mid to late '90s - Seinfeld, Frasier, Friends. Shows naturally sped up as they went along even if they only briefly touched this period -- like Cheers. Arrested Development was one of the first to truly capitalise on this by moving at a quick clip, jam-packed with self-referential stuff. I far preferred the lazier early seasons of sitcoms pre-mid/late '90s.