According to Christopher Booker, there are only 7 story plots. That means that we can't create a story without deliberately or accidentally copying important features of someone else's story. Perhaps the problem is not lack of originality, but successful branding. E.g. the new Poltergeist could be regarded as an original movie with an old brand. Similarly for all of the remakes of Spider-Man, Batman and Robin Hood, etc. Or, perhaps there is no problem.
The musicologist Sigmund Spaeth suggested that all popular music is a mixture of other popular music, so there can't be anything totally original there, either. He came up with the following as an example, sung to the tune of Yes, We have No Bananas (your favourite song, Ellie Roll?):
"Hallelujah, Bananas! Oh, bring back my Bonnie to me
I dreamt that I dwelt in marble halls—the kind that you seldom see
I was seeing Nellie home, to an old-fashioned garden: but,
Hallelujah, Bananas! Oh, bring back my Bonnie to me!"
There might not be much that is original and good right now, but that was probably true at most stages in history. Remember, the past is a heckuva lot longer than what we regard as the present, so it makes sense that most of the good stuff was created in the past.