I remember in the 90s when the onion was much less known, and therefore unclear to the reader that it was parody.

At the time, life made sense. So the onion coming out with articles about bill clinton putting monica lewinski in charge as the head of the national department of sexual education, it came off as very out of place in the realm of real news. MOST people read the articles, and knew something was amiss, even if they didn't know what the onion was. Still though, some people still believed the wacky absurd news articles, and it put a spotlight on those who had zero critical thinking skills. THATS what made the onion fun back then. Laughing at the boomers who got fussy over literal fake news. Back before the term "fake news" was a thing.

Now though? The onion still posts wildly unbelievable absurd stories, but because real life is wildly unrealistic and absurd, even people who fully understand what the onion is still fall for it. Simply by doing nothing differently, they are now far more believable, and don't immediately stand out as unrealistic anymore.