Because tennis isnt about just winning the French and beating one guy.How can either Federer or Djokovic have an argument for being the GOAT when neither had any answers for stopping one of their biggest rivals in Nadal at the French over the past 14 or so years? Federer's 0-6 and Djokovic is 1-6. And since Djokovic won it in 2016, he hasn't even sniffed a final there over the past 3 years, losing twice to a guy that Nadal bludgeons time and time again with relative ease in Thiem. And Nadal was thrashing both Federer and Djokovic at the peak of their powers at the French. So how can either of them be considered GOAT if they both only have 1 French Open title to Nadal's 12?
It's probably easier to say "Djokovic is the GOAT in Australia, Federer is the GOAT at Wimbledon, Nadal is the GOAT in Paris and Federer and Sampras are both the GOAT in New York. LOL