It depends upon the price point. If I'm investing in binoculars over $400, I'm going to want a lifetime warranty. A 10 year warranty? That's not very good, if you're talking over $400. Binoculars can easily last decades (even a lifetime) if well cared for. But things can go wrong. There is always the consideration of materials failure. It can be something as simple as a coating going from "velvet" to "sticky"... or a plastic internal shim ending up warping due to heat exposure, causing a problem with focus, or a dioptic detent system failing, resulting in loose turning.
My cheap old pair of Simmons binos had a stupid design choice--satin rubberized coating on various connector parts. It's a porro prism design, but one of those shallow downward sloping types that almost make it look like a roof prism design. Anyway, those pieces turned into a sticky mess. I just used some medical alcohol swabs. About 3 passes, followed up with a good standard countertop cleaner, and those parts turned into a semi-gloss plastic finish. No tackiness at all. The remaining rubber armor is still perfect. Totally saved the binos. My mother had a cheap pair whereby one of the internal lenses slipped out of place somehow. I didn't see any sign of dropping, no visible damage at all. But it could be just a non-abrasive "thud" might've challenged an internal bracket, giving way and allowing a lens to slip out of place. Well, once that happens... You could try to open it up and fix it, but for the price point not worth sending back to the maker. They're done.
But I'll bet anything you'll find many testimonies from people saying their 30 year old binoculars have never needed servicing and are working almost like new. Generally with high quality, it's almost a given. Still, some brands go above and beyond with their warranties. I saw one person's testimony with Athlon Optics. Their Cronus G2 UHD was dropped out of a moving vehicle. Yeah, it was a kid that did it. The father was upset, but took a chance. Athlon honored the warranty and instead of fixing them, they got a new pair in return. Granted the warranty doesn't cover "abuse beyond normal use," but sometimes these companies would rather turn the good favor in potential marketing. After all, here I am relaying this--that's free advertising.
