No, of course you're right, the "toy model" is exaggerated. I think it was more true in some countries than others and several decades ago, when there was no internet and the media were dominated by a few players (including the government itself, in many countries) all very much established.
Let's say that I suspect that democracy is a system that assumes public opinion to be directed so that it doesn't stray too much from a narrow range of possibilities. This can be done just by manipulating the Overton window.
In this toy model, Roger Ailes and Rupert Murdoch have zero influence over either the media or government?