well i think it is. laver won over 180 tournaments, 2 calendar grand slams and a calendar pro slam. all unmatched achievements. federer still has a heavy losing record against nadal.
rosewall is underrated by this list, he could easily be top 5, definitely top 10.
It's impossible to compare eras, though. Laver won 180 tournaments, but is that the equivalent of 180 tournaments today? I don't know. In 1962 alone, Laver won 22 tournaments. Federer hasn't even played
that many tournaments in a single year since 2003, when he was just climbing to the top. It's impossible to play that many tournaments today. The game is too grueling if you're making final after final. Plus, players wear down so much faster now (maybe due to the increase in hardcourts?). Players retire now in their early 30s and are past their primes by 28 or so. Laver didn't even peak until 27 and played until he was almost 40. There's pretty much no way Federer (or any modern player) can match Laver's record. The game has just changed.
I think the best thing to do is contextualize each player's achievements. We can't just say, "Federer doesn't have 180 tournaments like Laver, so he can't be the greatest." Granted, I still think Laver is probably the greatest player in history, but I think you're approaching the debate from the wrong angle.