Federer is a legend, but history won't name him the greatest of all time (GOAT). The GOAT debate should be decided in favor of the winner of the most major titles, and he's already been passed by Djokovic and Nadal, who are now battling for GOAT status.
Never mind the Grand Slam titles record, Federer is the GOAT both as a player and a human being. On the court, he's exemplified class, elegance, and grace, while seeming to play effortless tennis. Off the court, Federer was as humble as they come and he treated people kindly, which earned him universal adoration.
Federer has been a magnificent player and he's surely a legend, but fueling this very American "greatest of all time" debate is troublesome. It's impossible to compare different athletes in different contexts, meaning this discussion is purely a clash of fanbases. We should stop debating it and start enjoying and respecting all great champions.
There's a 50% chance that the all-time tennis Grand Slam singles record for men will be at least 24 by 2050, according to the Metaculus prediction community.