One may use the knife 'lightly' for 2 years and 'heavy' in the third only to discover that the blade fractures or the handle comes off etc. That would be a bummer.
Almost all knives I have offer a lifetime warranty including Kershaw, Boker, Kabar,
Leatherman, Victorinox etc. etc. I got used to it that knife manufacturers stand behind their product. Let's take Boker for example, they offer cheap chinese made offerings to German made ones ALL with lifetime warranty.
However, one of the most expensive knifes I bought -Fallkniven- DOESN'T have lifetime warranty and it stands out like a sore thumb. All their knifes are PREMIUM production knifes so why they don't offer lifetime is still really strange to me...
I still don't see why.
(I suspect it's because Fallkniven is small family business and they wouldn't be able to sustain a lifetime warranty).