Pete Sampras hits his forehand with much more topspin than Andre Agassi?You make some good points, but I want to dig deeper on this:
Firstly, the slowing of the courts is a matter of record. In fact, it began at the USO in 2002, making this the very last USO with the faster surface. See e.g.: Are U.S. Open Tennis Courts Even Slower in 2010?
Remember that Lleyton Hewitt, who loved fast surfaces, won his only USO in 2001.
Whatever about Novak today, if this was true, it would have been very noticeable in the matches Fed played against Agassi, especially the ones when Fed wasn't ripe and Agassi wasn't that much past his prime (such as the R4 match at the 2001 USO). But Agassi's extra power on the forehand wasn't apparent then; if anything, it was the other way round in terms of hitting through the court.
(And incidentally, regarding Novak's FH speed, we shouldn't forget that when he emerged on the scene, he had one of the biggest and best FHs going.)
Well, Sampras hit his FH with much more topspin than Agassi, so that kind of undermines your theory. Although admittedly, neither hit with the freakish topspin of a Rafa or even Fed.
In this match, it's not right to say that Pete beat Andre with the forehand. Pete was very reluctant to engage in rallies, so he hit a lot of wild shots: some were winners or near winners; some went way long, but the way he played them wasn't dominating at all. Sampras didn't win this from the back court at all.
You are on some GOOD stuff! 😂