There was a resurgence in the late 80s/early 90s with Phil Hartman, Jan Hooks, the blond conservative girl whose name escapes me, Mike Meyers, Jon Lovitz, Dennis Miller, and a little bit later that chubby guy who died of the cocaine overdose.
But yeah, after that, pretty much a fatal trend line.
The firing of Norm MacDonald was a sign of things to come.