Comparing to all the nagging options in a poll there's one ever-present issue in laptops that I have to deal with every day.
The only thing they need to do to fix most issues (and it's also in big part Intel's and AMD's fault), is bring back the modularity. I mean, socketed CPUs, actual RAM slots, non-soldered SSDs, replaceable WiFi cards etc. And no "whitelists" in case of HP/Dell.
I'm tired of telling customers "I'm sorry, your macbook cannot be upgraded. Period.", or "Replacing that dead CPU costs about as much as replacing the entire board, sorry", or "I won't be upgrading your RAM at least until the warranty runs out, cause we have to solder it".
Another big problem is power circuitry and low-quality batteries. Symptoms can range from random reboots/shutdowns, to battery stopped working altogether, but it's more and more frequent. Usually happens on consumer laptops right around the time when warranty expires.... for some reason... Few years ago it was a flood of 3rd and 4th gen mid-range laptops, now it's 6th and 7th gen all the same. What makes matters worse, is that most laptops nowadays have internal, non-detachable batteries. So, the customer no longer has an option to safely store a pre-charged battery pack in a drawer(to preserve health and minimize charge cycles) while using lappy in an office or at home as a small desktop.