While the "guarantees" on the package can be extravagent, few of them ever pay off. That likely is because we don't save the packaging and don't have any idea who to complain to when something happens - or we have so many packages we can't tell which one the device that failed came in.

The other thing shops do in my experience is to print the receipts with ink that fades, so by the time anything goes wrong, even if you've saved the receipt you can't read stuff like the date. I'm sure this is intentional. That's an advantage of shopping online, you get an email with the important stuff on it. Though of course to be safe you'd need to print it and store it safely - and then you are likely enough to find the seller isn't reachable any more, or liv in Kazakstan or somewhere...