. Part of USPS training for every employee is the chain of custody of Registered mail. It is as I stated the MOST SECURE. Someone pays when it is lost or stolen. A letter Carrier on a relay route left a registered package in a push cart while he went into a business, when he returned (no more than a couple of minutes later) the "Regi" was gone - he paid $70,000 out of his pay.
I am very familiar with deviant behavior is the USPS, just llike anywhere else. I personally knew 3 clerks who were hauled out in cuffs in one day at the same Post Office. But it is usually for money Orders. That is statistically the #1 area of fraud.
As for speed I told you at every step it is slow- why do you keep arguing that? The point is SECURE and that is the most secure. If you send $30Kpackages any other way , you are not thinking clearly. Priority has no security, there are insurance limits.
Your freind is exagerating and knows not what he is talking about - is he 'disgruntled'?.