Unfortunately, things have never been this clear cut. Emerson for example, had 12 majors and was not considered the GOAT by anyone. Laver has 2 Calendar Slams, but only one is really vaunted (Open Era one) etc. Pete being ahead of Rafa at 3 of 4 slams definitely says something. Remember, prior to the big 3 there were a few detractors who considered Pete's resume unbalanced because half his majors came at one event. Imagine what this means for Rafa.
Overall, what is more pressing for Djokodal is who ends up greatest of this generation, because in order to be eligible for the greatest of all time you must be the greatest of your time. From there, the discussion with the other GOAT contenders may be had.