What percentage of Laver’s slams were won on grass? Why was Pete considered GOAT in his time without slams on all surfaces?
The answer to these questions show the ‘surface distribution’ argument for what it is.... irrelevant
Those questions you asked sound more like a lack of analytical capabilities from you than anything else. When we are analyzing different periods, we are analyzing different scenarios that require some adjustment when we put things into perspective.
1 - During "Laver Era" all of the majors, with the exception of the French, were played on grass.
Is not about surface-wise. The whole different surfaces thing came in when we had the first major to be played on HCs.
That brings to 2 - Pete was considered GOAT because he was the biggest champion in not only one major (Wimbledon), but two (the US Open as well). He had a huge dominance on Grass - not as big as Nadal's on Roland Garros specifically, but he was quite unbeatable there. Pete had a dominance over the whole tennis that was not reduced to a particular event and/or surface.
This is something that Nadal fans can't accept. He's great, the greatest ever on clay definitely and surely, no matter the circumstances for that. But there's more in tennis than clay, and there's people far superior there. Period.