Yes, Rex, that would be the argument
It's a style of play I like very much, so selfishly I'd love to see more players do it more
I mean, I don't think it's TOTALLY dead. Like you said, there are players that you listed who are doing well. Federer can serve-volley when he wants to. You also have players like Roddick who realize that he is more successful when he comes in behind his serve sometimes to mix it up, etc.
It's also just a frame of mind. Players have to be convinced to do it