I guess it does get harder and harder at GS level after 32.
he fished out over $71 million last year. his net worth has to be approaching around $400-$500 million.
he has achieved everything that one can possibly achieve in modern tennis. maybe he is smart enough to know that slams will be difficult to come by so he does not work as hard as he used to.
and we forget sometimes that he has two beautiful daughters and a wife. perhaps some of his focus is on the family now.