JLF's, like every joystick, just needs to be maintained.
They will last you forever with the proper care, and maintenance. I use a wide variety of joysticks for multiple games that require it (i'm a stickler for using the controls the game was designed for). For JLF's, I make sure I clean and re-lube the parts every so often. Really, the only thing that may stop working over time is the switches...but that's the same with every joystick. Luckily Sanwa products are in abundance these days, so finding a replacement part for the switch PCB is easy. Everything else is made of high quality metal and plastic, down to the even the housing.