“But, to be fair, Hollywood comedies were generally straight-forward affairs in the ‘80s. Think Blues Brothers or Fletch. Fake documentaries weren’t a thing.”
Albert Brooks had already made Real Life in 1979 (parodying the PBS reality show about the Loud family).
https://www.youtube.com/watch?v=W8ReqVoSZOM
Woody Allen’s “Take the Money and Run” was also a “fake” documentary