So I see two takeaway questions: would we be fine/better off without mass media funded by advertising(it's obvious what my answer to this would be since I don't generally listen to it or watch it, though I acknowledge it going away won't likely happen).
And the second, would content we like to consume/ be worthy of consumption be produced anyway, and my contention is that it would still, just like it did in the past and continues in the current (some free, some paid for), as can be seen in the history of books, early internet, street art, leisure, bloggers, hobbyists, cinema, documentaries, etc.
There might be a third point of mine, which is that we're actually suffering from a glut of content and competition for eyeballs: so to me, worrying about that content disappearing is a bit like worrying about dying of thirst while drowning in a freshwater lake.