True enough and don't forget Laver won the Pro Grand Slam in 1967 of Wembley, the US Pro, the French Pro and the Wimbledon Pro which was perhaps the most important tournament in the history of the Pro Tour.
Frankly I don't understand why every discussion seems to deteriorate into a hypothetical battle between Laver and Federer. Both are great players and it's not necessary to demean either one.
I have seen Laver numerous times in person and on television is I can say he did things with a wood racquet that I've never seen before.
There seems to be a controversy on how many majors Laver would have won if there was Open Tennis. Many say Laver would not have won any majors prior to 1963 and that his majors total would be greatly lowered. Perhaps, perhaps not. But here's a few facts, Laver in any level of competition has been number one and a clear number one. In 1963, when Laver first started it's obvious that Laver was inferior to Hoad and Laver, perhaps other players also. What is also a fact is that Laver quickly rose to number two in the Pros by at least the end of the year in 1963. Laver was arguably number one in the Pro Ranks in 1964 so it took about a year for Laver to overtake the top pros!
Laver was one of the most versatile players I have seen. This is an opinion of course but many who have seen the Rocket would agree with me. So he could adapt to virtually anything. If we had the hypothetical that Open Tennis was always around you would assume that Gonzalez, Rosewall, Segura, Sedgman and Hoad would not be the giants that they actually were because they would be playing overall inferior competition in the Open Era instead of the all world lineup they face every week, even in the first rounds of tournaments.
We all play to the level of our competition and the competition would be weaker if there was never a Pro Tour and there was just Open Tennis.
Laver I assume would be playing Pancho Gonzalez at an earlier age and would be raising his level in order to compete with Gonzalez who may not be the super great that he was in actual life. No doubt Gonzalez would be great. Laver also would be playing Hoad and Rosewall and would know that to compete he would have to improve his play.
I do believe is that the cream eventually rises to the top. I believe a young Laver may very well have won a number of majors in Open Tennis was always around. Perhaps Laver would have won a lot more classic majors as perhaps Gonzalez, Rosewall and Hoad.
The thing is that despite perhaps having a superficially better record in majors I don't think they ever would have been as good as they were in actual life. The situation in those days was unique in the the top pros constantly played against each other. Many of them were all time greats like Kramer, Gonzalez, Rosewall, Hoad, Segura, Sedgman and Trabert. If you play at this level all the time you have to be a far better player. Gonzalez for example was beaten badly by Jack Kramer in is first pro tour by a score of 96 to 27. Gonzalez improved greatly playing Kramer and eventually became number one and stayed arguably the best player (perhaps not officially number one in the pros but the best player) for around a decade. I doubt if Gonzalez would have made this quantum leap type improvement if Open Tennis was always around or if he remained an amateur like Roy Emerson did.
Just some points to think about.