Not at all necessarily. It could be, but it is definitely not necessarily true.

It depends entirely on usage patterns and attitudes.

I just used a piece of material that was sitting on the shelf for at least ten and probably closer to fifteen years. I'd purchased it as an off-cut from a supplier just on a thought of "this might be useful, and it's a good deal". Carried it through two moves and never got around to using it. Suddenly it turned out to be the perfect thickness for this one customer project when the expected material didn't work — never could have predicted it. Not only that, but when I went to check how much it would cost today, I literally cannot find that particular thickness. It literally saved by butt on this job.

OTOH, I do have other materials I've used once or twice, but the needs have shifted so they're going on Craigslist for free.