claims that the under 40s expect everything to 'just work' and have no idea what to do when things go wrong
I have a Samsung computer monitor that isn't properly detected if I use the DVI cable, although the VGA cable works fine. This prevents Mac OS from detecting the monitor, and confuses Windows. (The technical details: it's not transmitting EDID over the DVI connection.)
The quick fix for Windows worked for a while, but a driver update changed how things work and would be constantly confused by that monitor. The proper fix requires opening the monitor, using a multimeter to find what's wrong with the DVI connector, and fixing or replacing it. This is not something you can do on a weekend, as opposed to fixing a larger appliance.
The problem isn't around knowledge, but that it requires equipment not expected to be in a normal home. A house can have tools available to fix large mechanical objects, but not extremely delicate electronics that require an electron scanning microscope to properly fix. The repair costs for devices usually indicate that the whole device has gone bad as opposed to an easily swapped component, meaning the manufacturers also have trouble getting things to work as well.