If people don't feel like paying for musicians and the like, than it's a signal to the market to stop supporting musicians and force them to work other jobs that people are willing to pay for.
If that what it meant to be, than it will be. Copyright will merely submerge the will of individuals into the underground illegal music scene and not solve any problems for musicians at all.
They can keep busting pirate networks all they want, it won't change a thing in the long run. Musicians will die off and soon we will be left with a frozen archive of musics, though a very large library.
It doesn't matter that much to me anyway. I'll never be able to get all the favorite songs in the world. I'll never be able to remember enough in my lifetime. I am pretty content with this scenarios.
I don't think what artists fear will come true. Instead, many of them will probably find ways to make a living.
For me, it's the same cognitively. There are still tons of artists and songs to discover, too much for a lifetime, and too much for the limited memory capacity of my brain.