does not make it even nearly like the max effective rd that CAN be controled, by a highly skilled man. It's just the best that can be handled by the typical lame, who won't practice enough, that's all.
Now, with the right bullet, at the right speed, the 9mm or 38 can be made to be considerably more effective than the current factory offerings (like about twice as powerful-effective) with the same or less level of recoil. However, such solid copper bullets, at 2200+ fps, are AP, and lots of cops get shot with their own gun, or their partner's gun. So they dont want to carry AP ammo in their sidearms, much less want anyone else to have such handgun ammo. So there's about zero demand for maximally effective handgun ammo, because that ammo is AP on Kevlar vests. Consequently, no large, or even small, commercial ammo maker is going to offer such loads for sale.
Only the most committed fan of ccw will take the trouble to make such ammo for himself, so almost nobody is aware of its much greater potential (than standard ammo). Such a man also won't restrict himself to a .38 or 9mm, so his research goes into what he can get out of a 357 Sig pocket auto, or out of a 10mm or. 45 Belt gun. So there's very little work being done on maximising the effect of loads likely to be used by the "common man". That's why so many say that there's no difference in handgun loads. They are right, about TYPICAL ammo, but they are quite wrong (and provably so) about the top loads that can be had.