The H2H between Federer and Nadal was most significant in 2010 and again in 2013, when Nadal was on top of the sport, and him getting to, possibly even surpassing, 17 majors was considered a matter of when, not if. Now that few believe he has 3 more majors in him, its significance wanes.
People, journalists and analysts especially, are prone to jump the gun and declare guys the greatest based on the present landscape of the sport, projecting that forward as if nothing changes in tennis, and penciling guys in for accomplishments they haven't achieved yet, but speaking of them as if they already have.
Consider this timeline...
End of 2007 - Federer is sitting on 12 majors (amassed in 4 1/2 years). McEnroe declares him the greatest, certain that he will surpass Sampras' 14 majors.
End of 2008 - Federer nearly goes major-less. Djokovic arrives in Australia. Nadal crushes Federer at RG and then dethroned him at Wimbledon, but Federer manages to win the U.S. Open. Doubts begin to surface.
Australia 2009 - Nadal backs up his Wimbledon triumph by beating Fed in another epic 5-setter. Federer is stuck at 13. McEnroe wonders if he will ever win another major. Sampras is once again the greatest.
Australia 2010 - Since losing to Nadal here in 2009, Federer makes the next 4 major finals, winning 3 of them. He finally wins the elusive RG title and then surpasses Sampras at Wimbledon. Only a close loss to del Potro prevents him from being the first man in 40 years to hold all 4 major titles at the same time. He is clearly the GOAT now, according to McEnroe. More majors than Pete and several more likely to come.
End of 2010 - Nadal sweeps the rest of the majors. Sits at 9 majors. Federer's results suddenly falter with previously unthinkable QF losses. Nadal is expected to dominate for the foreseeable future. Can he catch Federer? Is Federer done?
End of 2011 - Djokovic 2.0 crashes the party and has a first 9 months that was arguably better than any Federer or Nadal had ever produced, dominating Nadal, beating him in several successive finals.
Australia 2012 - Djokovic beats Nadal once more, giving him 4 of the last 5 majors. Dominance is predicted. Federer officially done.
End of 2012 - For the one, and only time, the Big 4 split the majors. Federer wins a record tying 7th Wimbledon and 17th major, briefly reclaiming #1 long enough to surpass another Sampras record and become the only man to spend 300 weeks on top of the sport. This, once again, prompts Johnny Mac to proclaim him the GOAT.
End of 2013 - Nadal misses Australia, but returns in February to steamroll the tour with some of the best tennis he's ever played, turning the tide against Djokovic. The only hiccup is an early exit at Wimbledon. He sits on 13 majors. Johnny Mac thinks you can already argue that he's the GOAT. Federer's record is destined to fall.
The present - Nadal won his 14th and last major to date at RG in 2014. Djokovic has yet to win more than one major in a year since 2011, yet was being touted as a potential CYGS winner after his QF win over Nadal at RG. Federer hasn't won another major since Wimbledon in 2012. Players not in the Big 4 group have won 3 of the last 6 majors.
What will happen next? Who is the GOAT? Only one piece of advice I can offer...don't ask John McEnroe!