hasnt it been agreed for a long time that all stories are just the same 6 stories, or something?
that said, 'remix culture' has taken a rise in recent decades - you got fanfic, you got DJs, you got parodies and remakes, just about everywhere. you got stuff like wicked (which is a musical based on a book inspired by a film based on a book) and the shadowhunters (the tv reboot of a movie series based on a book series which was an edited version of harry potter fanfiction and lifted from several other writers) - both are very good; popular, and enjoyable.
maybe too much weight is placed on originality. or maybe people are just misinterpreting originality - its not about fathoming an idea from the void that has no similarities to anything ever. i think its about bringing something new to the table. thats why things like community and homestuck do so well - they take everything that already exists, and flip it on its head one way or another.
i think, if anything, as storytelling becomes more accessible through the availability of technology and sites like tapas, were gonna see a lot more very original stuff, because were opening the gates to the narratives and perspectives previously ignored (see: why aboriginal australian art is the most exciting thing to hit contemporary art since picasso)