If you use the gun a lot, especially drawing from the holster, or shooting around barricades, the plastic sights will eventually let you down.
But fiber optics and such can, too.
It all depends on what you do with it.
The sights that hold up the best are all steel, if you need them to be really durable.
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”