Who Do They Sound Like?
First and foremost, as a creative person myself, I think about the creative aspect of things. And from where I sit, it seems like it's almost impossible to break new ground anymore. After roughly a hundred years of recorded music, and over 60 years of rock and roll, it is to be expected.
It's the first thing that people ask you in a record store when they are curious about a new group: Who do they sound like? After all, they gotta sound like somebody.
Now it's not like any one group sounds exactly like the other, but if you really study music, you can always think of one or two groups. Usually artists that were in the game early on, making up the rules.
My point: You can't cross lyrical boundaries any more than Bob Dylan and Joni Mitchell. You can't get weird and push the limits of yourself and your band more than Frank Zappa. You can't extend the limits of on-stage jamming very far past the Grateful Dead and the Allman Brothers.
It's not that artists can't do anything new, and I'll spend the rest of my life listening to them try, but it's tough to be the grandfather when you're part of the fourth generation.