Few things going on:

Basically every gunmaker is prioritizing making full guns over making parts available, because the guns are selling (to distributors at least.)

The Italian factory only makes certain things in batches every couple of years from my experience.

Beretta Italy in particular probably prioritizes defense and police contracts over consumer sales.

The hayseeds at the Tennessee factory are still trying to figure QC out.

The Beretta 92 is stronger than it has ever been with how many different models and clones are out now, I’d say.