Late to the party, but I’ll toss my two cents in along with what already has been said. The HK USP and direct offspring are (IMHO) perhaps THE most robust pistols ever made. I was issued 2 over the course of nearly 20 years. Ran the absolute snot out of both. The first (before the firing pin was redesigned around 2006) had an HONEST 50K thru it. The second (newer model circa 2012) likely an honest half of that. I had 2 firing pins fracture on the first prior to the redesigned radius cut for the firing pin safety. After the new pin was installed (and subsequently the second pistol for its entire life) never had another breakage. The Flat Spring broke once in the first gun, rendering the LEM inoperative, although the long-stroke full DA pull was still available. Never had a SINGLE ISSUE with the second gun. From what I’m told, most of the time the Armorer’s sloshed the frames around in cleaner and blew them dry. The design using the friction plates ( for lack of a better term) is absolutely genius. I have a personally purchased USPc and USP 45FS that will never get sold off and will always be counted on to go bang. I would think that complete disassembly would cause more risks than it’s worth.
Edit to add: I think the first was simply replaced do to age/round count although it was working fine. Went thru training once. They asked me how many rounds I had thru it. (Probably looked at serial number and issue date.) They simply said “OK, we’ll get you a new one.” Signed out the old one, signed in the new one...done. 🤷*♂️