I've never seen a Mossberg or Remington pump gun worn out to the point of being unsafe or unreliable.
I have seen Model 12s and 97s thus,though it takes a couple hundred thousand rounds to get to that point.
Shotguns are simple devices as firearms go. On pumps, the things that gang aglay are shell latches and carriers, small springs and firing pins.
In half a century of pumpmanship, I've broken two firing pin springs, had one shell latch come adrift(Still functioned fine and a good smith fixed it gratis) and seen one firing pin that broke being dry fired in cold weather.
A US made pump, from the Maverick(Yeah, Mexican labor on US machines) to the older Winchesters and Remingtons lasts much longer than we do.
My wingshooting 870, Number Six, is older than my spouse. The paltry few thousand rounds put through it so far have merely slicked it up a mite.
My grandkids, if any, may think it archaic but it will work, even if we run a case a shells though it each and every week, and take it to Argentina yearly.
Same with the others. US made pumps love high round counts.