“In 2015 worldwide TV sales fell by 11%, young people watched 10 minutes less television a day and in the US research showed that 62% of adults watched online video every day.” But viewing on other screens more than compensated. http://www.euronews.com/2016/04/06/how-is-tv-consumption-changing-around-the-world
The TV sales drop speaks loudly: the continuing increase in population and much faster increase in sufficiently wealthy population, the change from analogue SD CRTs to digital HD flat panels, and the dampening of demand cyclicality by the desynchronization of the economic cycles of various countries from each other should all have caused a substantial increase in sales. Eventually the diminution of conventional TV will reach even parts of the world where it is relatively minor today.
It is facile to say that viewing will shift to different sources or screens. The more interesting question is the economics. How many independent OTT services from channel operators can be sustained separately from each other or in substantially à la carte models like Dish Network’s Sling? And if they cannot, and must rely on aggregators like Netflix and Amazon Prime Video, will the low pricing deplete revenue until the more popular programming cannot be paid for? So far, both traditional broadcasters and the OTT aggregators have adapted, but this does not mean that they always will. At some point there might be a shakeout just as macroeconomics predicts (easy market entry leads to minimal profits).