There wouldn’t be any scale to adtech either without massive adoption. If adtech collapses as a viable stream, something will quickly take its place.
This is a human behavior issue. You would need to change the behavior of billions of people before the ads model gets affected.
Music and movies are highly repeatable and have production costs that users recognize and value. News and general content is not valued the same so nobody wants to pay for it. The severe dropoff in any paywalled site shows the effect of charging for news.