With how big Filler's gap is in Fargo (863 vs. Gorsts 850), it is statistically clear that he is the best current player in 9-ball. Anyone can come up with cherry-picked examples where someone else is better (e.g. only considering a certain tournament for the last few years), but if the definition of skill is your average performance over the long run across all 9-ball tournaments, Fargo is the most accurate measurement that we have, especially for top 100 players who have a lot of games in the system and regularly play eachother.
Fargo doesn't account for performance in big events and pressure.
If there was a Fargo system in the NFL, Josh Allen would be rated higher than Patrick Mahomes.