"Content costs money to make so companies need money to make it" is a true statement.
"Companies therefore must run advertisements to make content because a significant portion of the target audience does not want to pay for it" does not follow from that.
There are many industries that typically do not run advertisements for their content - book publishing comes to mind here - and they seem to get by just fine.
90% of everything is crap, so 90% of entertainment disappearing because production houses and producers stop whoring themselves out to Madison Ave and big brands is a net positive for society. Make the 10% of things you can get funded by the target audience without having to mentally and emotionally manipulate them (which is what advertising is) and you'll still have too much content for the average person to consume.
Advertising is immoral, and advertising to children is both immoral and explicitly evil.