Between 04-09 who upset him? Kuerten the 3 time RG winner who rolled back the years? Del Potro who was GOATing and needed 5 sets?
Doesn’t compare to the kind of players he lost to post 2010 AO.
It's isn't even in the same ball park.
2013 Wimbledon: Federer lost to Stakhovsky in the 2nd round, who then lost to Melzer in the next round, who then lost to Janowicz in the next round
2013 USO: Federer was stomped in straight sets to Robredo in the 4th round, who then was stomped in straight sets by Nadal in the very next round.
2015 AO: Federer lost Seppi in 4 sets in the 3rd round, who then lost to Kyrgios in the next round, who then got smoked by Murray in straight sets in the next round.
2004-2009 Fed. Missed 4 finals and 1 semi during this 6 year span.
2010-2015 Fed. Missed 18 finals and 10 semis during this 6 year span.
Longest streaks:
2004-2009: 10 consecutive slam finals, 22 consecutive slam semis
2010-2015: 2 consecutive slam finals and 4 consecutive slam semis.
It wasn't Nadal and Djoker that prevented Fed from missing all of those slam semis.
As far as Kuerten goes, that guy was an absolute beast on clay when he was on. Kuerten on clay reminds me a lot of Safin on hard courts. Both players could slump badly. But when they were on, they were extremely dangerous. And Kuerten's game was beautiful on clay. His weakest shot by far was his serve, which was in the low 120's.