Oh, no doubt that for a large sample size, i.e. many hundreds of divers over a long time period, you would see some statistics that would support the benefit of nitrox. And this is exactly my point: of course there is a statistical benefit to nitrox, as large sample sizes demonstrate.
And this complements my point that for any individual, it is impossible to tell whether or not nitrox is truly beneficial for one specific dive. After using nitrox for a particular dive, there is no way to measure whether or not air would have also been okay for that particular dive. And there's no way to guarantee that for any particular planned dive that using air would result in DCS while using nitrox would not.
Long term statistics for a large sample size are a different issue.