I think there's something to the sitting idle angle. My launch joycons started getting drift 4-5 years ago. I did the usual clean out, then cut some plastic to put more pressure on the stick back plate and they were surprisingly fine. Two years ago I picked up an OLED, and my primary switch got very little handheld use after that.
Fast forward to a few weeks ago, when I grabbed my launch switch to upgrade the firmware and run some tests. The sticks were basically unusable. I have a couple sets of Hall effect sticks laying around, I guess now is as good a time as any to put them to use.
I cannot confirm nor deny this, but the fact remains that Deloreans still exist today. And I do not recall ever hearing any stories about rust. Which, given its infamy, one would think would have been part of the lore by now if it was a thing.