This is another of the long line of threads that think somehow a fraction of an inch extra room in the string bed is going to make a huge difference in hitting a ball that has a diameter of about 2.5 inches. It doesn't make that much difference.
This thread is based on a silly premise anyway. Federer was number one for so many years. He can only go down as he ages. That's just the way reality works. A frame change won't fix that.