But it isn't. China and India are going gangbusters. Japan is thriving and doing strong work. Nigerian cinema is projected to hit 3 million ticket sales for the first time this year. The UK--is at least stealing work from Hollywood with tax breaks. Korea had a rough patch, which they turned around by doing more mid-market films.
The US studios problems are unique, which at least suggests that the answer lies in the failures of their leadership. Perhaps their long project of abandoning original mid-market films to push bloated huge special effects heavy franchises was ill-advised. It's almost Like having a portfolio of 10-20 reasonable original bets is better than investing everything in a single expensive "sure-thing" sequel it increasingly seems like no one actually wants to see.
So I agree that Hollywood has stopped innovating, but am dubious that any other problems has much to do with Youtube (as much as I enjoy YouTube).