"Its like how they make cop shows and movies where the criminals are all Machivellian geniuses to make police seem more competent. "
Many shows and movies are specifically about catching the criminal geniuses that regular cops can't.
And very often (EG CSI, Bones) the criminal is pretty normal, it's just hard to figure out what happened.
House MD doesn't make medicine complicated to make doctors look better. If it's a cop like Harry Bosch, cold cases are complicated by time. Bosch doesn't (just) succeed because he's smart, he succeeds because he's persistent, and often breaks Da Rulez.
Which has gotten himself and others hurt and killed.
Also, who wants to see "oh, the husband was found with the murder weapon in his hand, standing over the body, and he was caught in 4K stabbing his wife. Case closed. "?
What will you fill the other 39 minutes with?
Writers have to complicate the plots to make them entertaining.
There's also plenty of complex mysteries where the investigator is not a cop, or even a private detective, technically. And the real cops will go "drop the case". Several times.
Fincher's "Zodiac" focuses on journalists, and some of their lives get wrecked by the case.
Robert Graysmith lost his wife and the kids. And wasn't even a reporter! He was a cartoonist!
And there are several famous mystery works where the answer turned out to be SIMPLER than the investigators thought.
Very often in mysteries, there's a moment where the investigators realize there was something simple they overlooked the whole time. Maybe they rush to stop the bad guy and barely make it in time.
They can't make the cops hyper-competent without losing drama. Which is always ignored.
Bottom line: This is a stupid claim made up by the sort of people who call everything with cops "copaganda".