You don't see law enforcement agencies using last century ammo.
You won't see me using last century ammo.
Modern JHPs are vast improvements over their predecessors. I'll go with modern technology.
There are also a lot of handgun cartridges that are not commonly used by law enforcement and thus haven't received the "vast improvements" that cartridges like 9mm, .357 Sig, .40 S&W, and .45 ACP have. For these cartridges, "last century ammo" is oftentimes still the best available.
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar