I've been using my home desktop for many years now, with a variety of disk drives, and over those years some of those disks have failed (without data loss, because I use software RAID mirrors). Some of the time, those failures have happened when the HDD was still under warranty, but despite that I've never bothered to try to return one for a warranty replacement. This is strikingly unlike work, where we routinely return failed drives that are still under warranty.

Historically there have been two things that changed my behavior at home. The first is that when a disk drive fails in my home system, my priority has always been to restore redundancy as fast as possible. Sending a drive in for warranty replacement and waiting for the new one would take weeks, and I don't want to run a non-redundant setup for that long, so I've always gone out and bought a replacement drive immediately. The second is that a lot of the time, the failed disk was old enough that the replacement HDD I'd be buying was bigger, which typically meant that I had little immediate use for a smaller than I now wanted warranty replacement drive.

(In retrospect, spare HDDs for backups were one use, but I'm lazy.)

Neither of those factors have historically applied at work. At work, we've always maintained a spares pool for disk drives, so we already have an immediate replacement for a failed drive and then the new warranty replacement drive can be cycled back in to the spares pool. As for the potential size mismatch, there are two mitigating factors; we haven't changed the size of our disk drives very much, and we can usually find a use for smaller drives as system disks and the like. System disks for our servers merely need to be 'big enough', and it's okay if they're mismatched in size (although we prefer them to be matched).

This generalizes for more than disk drives, but disk drives are the thing I've had fail at home so far. If I had a power supply failure or a CPU failure or the like in my home desktop, I wouldn't be able to wait for a warranty replacement; I'd be buying something right away.

(These days that argues strongly for keeping older, good enough hardware around to use as a fallback, as new hardware becomes increasingly unaffordable. If I had a spare desktop I could press into service at home, I could wait out a warranty replacement. Although my current home desktop is so old that any five year warranties expired years ago.)

At work, we make sure we have spares for servers and other important things even though it costs more, because we have to. One reason we can afford to do this is that we don't need all that many spares; a couple of disk drives or servers can be the spares for a whole collection of in production ones, on the assumption that we won't lose too many at once. At home, I have so few disk drives, desktops, and so on that a 'spares pool' would be much bigger relative to my active stuff.

(This is partly because I have only a single home desktop. There's lot of people with multiple home machines and so on.)

PS: Long warranties are still a useful signal from vendors even if I may not take advantage of them at home. A disk drive with only a three year warranty instead of a five year one may well last much longer than five years, but that difference is a suggestive message.