Although I agree with some of your analysis, I don't agree with your implied premise or your conclusion. As a preliminary matter, however, I want to point out that, in my view, there is no such thing as a GOAT list. By definition, "the GOAT" is the one person who is the greatest player of all time, to the exclusion of all others. By definition there can be no GOAT list.
On the other hand, a GOAT contender, or candidate, is one of whom a reasonable argument can be made is the single greatest player of all time, to the exclusion of all others. A GOAT contender or candidate list can only exist when there is a reasonable basis for uncertainty about the one person who is the greatest player of all time, to the exclusion of all others. Further, the question of who the GOAT is, or whether there is uncertainty about whom the GOAT is, depends on the criteria used to determine the GOAT. This leads to the more substantive parts of your post.
Your conclusion,
anti, is that:
. . . it is clear that at least Federer is better than Sampras. [Really?]. Federer’s records are better in almost every department. In each major (AO, FO, BO, USO) Federer has a superior record, even in the British Open where Federer has 7 wins, 3 finals, 1 semifinal and 3 quarterfinals, whereas Sampras has “only” 7 wins, 1 semi and 1 quarterfinal.
And the great difference between Federer and Sampras is their record in the FO : 1 win, 4 finals, 2 semis and 4 quarters for the Swiss against only 1 semi and 3 quarters for the American. In the ATP world tour finals, Federer’s record is also better and in “Super 9 - Masters 9 - Masters 1000” as well. Among great events, perhaps only in the Davis Cup, Sampras had a possibly better record but he was helped by his teammates.
You do engage in some minor analysis of Sampras' and Federer's relative strengths and weaknesses, but then abruptly abandon that analysis by returning to analysis of relative records repeating your conclusion anti that: "Federer is surely a greater player than Sampras."
I disagree with your implied premise (your criteria for determining the greatest player), and with your conclusion. In my view, the better measure of the greatness of a tennis player is his peak level of play if it was sustained for a reasonable period of time. In other words, if a particular player played at the highest level of tennis ever played, and sustained it for a reasonable time, then he/she would be "the GOAT." I would also proffer that other important figures have used similar criteria. For example, Kramer thought Budge was the GOAT. Segura apparently thinks that Gonzalez was the GOAT. Laver and Rosewall have expressed their opinions that Hoad was at least the pre-open era GOAT. McEnroe was calling Federer "maybe the greatest of all time," (or words to that effect), as far back as 2004. Certainly none of them had the greatest records at the time these opinions were made.
Let's assume,
arguendo, that Sampras won only 3 Wimbledon, 3 U.S. Open and 3 Australian Open titles over 3 consecutive years. Let's further assume that in those 9 events, Sampras was so dominant, and his level of play so high, that he never lost a single set nor had to play a single tie breaker, and that he was similarly dominant on the remainder of the tour and was ranked #1 for every week during that 3 year period, and then retired. How would that compare to Federer's current career record. In my view, it would clearly fall short in virtually every respect. Yet, at the same time, in my view, it would probably make Sampras the GOAT, the single greatest player of all time, to the exclusion of all others, including Federer because it could reasonably be argued (it would be virtually indisputable), that he played at the highest level of tennis ever played and sustained it for a reasonable period of time.
That was an extreme hypothetical. But, in my view, Sampras' actual peak level of play was higher than that Federer's at least at Wimbledon, the most important, most prestigious, event in the game during both of their careers, and possibly also at the U.S. Open, the second most important, most prestigious event in the game during both of their careers. Further, in my view, Sampras' peak level of play on other faster surfaces such as indoor carpet was higher than peak Federer could have played on those surfaces, for,
inter alia, the reasons you state in your post, in addition to which I consider Sampras to have been the stronger, faster, more explosive athlete between the two.
It is not disputed that Federer has an overall better record than Sampras, in part because his prime has lasted much longer than Sampras'. It is also not disputed that Federer played at a higher level than Sampras on clay and today's slower hyper aggregated hardcourts, at least in part because Sampras made a conscious decision to develop his game to succeed at Wimbledon. But, that alone is not enough to clearly separate Federer from Sampras as a GOAT candidate. In my view, their peak level's of play were fairly evenly split between the faster courts that Sampras dominated in his prime, and the slower courts that Federer dominated in his prime. For that reason, I do have a GOAT candidate list which includes players any one of whom, in my view, arguably, played the highest level of tennis ever played, which includes: Federer, Sampras, Laver, Borg and Gonzalez, in no particular order.