I have lots of parts I have stored but never used for a decade or three.
OTOH, I have had cars that did need parts. It is kind of like bad juju to lack a spare (especially bearing in mind that most of my fleet are oddball cars with no ready parts source) - if you don't have one, guess what will break.
Example - in the late 1970s I had a water pump go out on one of my old MGs in Northern California. The pump was specific to only 2 years of engines. I made it from Crescent City CA to Portland Oregon by carrying a gallon of water and running no faster than about 50 mph (boring). When I got home, I picked up a new water pump and put it in the trunk for future trips. It has been there for the last 36 years and I have never needed another water pump, ergo the engine spirits have been placated.
Same thing with rare alignment tools, perhaps? And if you do get it, you can loan it to others less prescient than you.
Similarly, some clients of mine opened their own GM based shop a couple of decades ago when they left a closing dealership. They inherited lots of GM specific factory tools. When they folded their business last year, the majority of them went into the dumpster still in the box, unopened by them. But if they hadn't had them, who knows..........
