Most of the younger generation has grown up around the internet. YouTube, MP3 players, the iPhone, Netflix... all game changers that have shaken up the entertainment industry and journalism to their cores.
Think about how radically different the world is today as opposed to 1998. There are options today that would have been unfathomable, even as Matt Drudge was shaking up the journalism world with his news aggregation site that also broke news.
Fox News will survive, but in order to do so, will need to adapt. Yes, there will be an eventual audience drop, but every outlet will be experiencing that soon. It's not rocket science. Comcast, Disney, Viacom, CBS... and even Nexstar, TEGNA and (gasp!) Sinclair... will all have no choice but to change with the times. Some will be successful, some won't. It's the nature of the beast.
What Fox News has done by dominating the ratings in an unprecedented scale can truly be considered as the final hurrah for traditional linear broadcasting, regardless of the content or political viewpoint. It is a rather extraordinary achievement that we will never see again.