Uh, the Hays Code is actually a premier example of "Industry Self regulation", as well as it's replacement, the equally absurd and incestuous MPAA ratings system.

It's the exact "Industries have an incentive to self regulate" talking point that conservatives have long used to say industries should be less regulated

And you are pointing to it as an example that we shouldn't use the government to regulate media.

Meanwhile, I think the FCC does a pretty good job, where their regulatory bar is "You cannot blast boobs or these swears over the public wireless spectrum, everything else is fair game", including an entire TV channel called "Fox News" which has had to argue in court on at least one occasion that nobody would assume any program on "Fox News" was news, rather than entertainment.