Infinity's ITS data collection is one of the best in the industry, its true, and something to be respected.
Infinity also has close to 50% winrate among all its factions, which is also impressive, but as several commenters have already pointed out, is more related to every model being built off a common build formula, with stats, skills, and equipment costing the same for every faction. Some models receive discounts on some characteristics, but in general, every model in the game is on the same playing field.
Its worth noting however, that despite having the incredible tool that is ITS, Corvus Belli effectively does no balancing AT ALL, post-release. Once printed, 99.9% of models will never get updates until their faction gets an overhaul, which has a timescale of 3-5 years. This means underwhelming models remain ******, and great models remain top-picks effectively forever. Games Workshop actually balances their games very aggressively compared to CB already.
The only thing which CB has admitted to using the data provided by ITS for... is deciding which factions to discontinue, based on low player count. I don't think anyone wants that kind of feedback applied to Games Workshop games.