I have been a die hard fan of Roger Federer from W 2004. I have never said, not even once, that Roger Federer is the GOAT. Simply because I don't believe in GOAT. It's difficult to compare eras. Players used different racquet, played under different conditions and technology, so for me it's a silly thing to say that one player is greater than all without a shade of doubt. It's a huge disservice to the legends of the past to anoint Roger Federer as GOAT
Sure, you can compare across eras. Its not like Borg and Pete have 18 majors and won all majors and won slams past ages 35. Then, sure they are too close, but now no excuses. Agassi could win all four and be nr.1 at age 33, so no excuses for Pete. And even without the French, Pete still isn't close to 23 consecutive semis.
Borg too, if Connors from his era could play at age 38 lol, no excuses for Borg. And Borg won channel slam 3 times, much harder than to win USO and W, so no excuses for him not to win. Even if you give Borg 3-4 AO titles, still not close to 20.
And Borg and Pete are only Fed's goat competition, so not that many people left. Djokovic and Nadal are from the same era, so we can easily compare them with Federer.
So, the only ones left are Laver and Rosewall, ok I give you that, you can't compare those, but you can split eras. You can say they are the best in classic era, Fed is the best in the open era.
So, I don't see why Fed can't be at least the greatest in the open era, nobody is close for now.
Even weak era theory doesn't hold up, Fed has 30 GS finals and billions of semis, you don't even play greats before the finals, so there are no excuses for others not having those stats.
Sure, sometimes having an extra great in your era can make the difference between slam wins, but no difference between making GS finals and semis!!!