I don't miss Rafa at wtf emma darling. he has nearly killed himself trying to dominate the clay circuit for a whole decade.
it takes too much out of him during the season and you can see the results now: injures and ailments.
and now the back issue is resurfacing again. he has to get off the hard courts and say goodbye to his career at this point.
Since he wins majority of the the clay tournaments, it does take a lot out of him. And he's been doing it for years now so that's very telling. In fact, Nadal hasn't played a full season since 2011. Doha has saved his resume this year though since it's the only hard court title he has won this year outside clay.
Federer does his scheduling really well. He never burns himself out but when he does he typically loses. Remember how he couldn't sustain against a fired up Cilic at the USO. That's due to the fact that he had a very logn match again Monfils. So the reason why Federer is still playing well and winning titles is precisely that. He knows how to schedule well. It's only Nole who schedules very well other than Federer and that's why he's been on top of this game for a while now.