Stuart Noble wrote:

Is there any other area of manufacturing where obsolescence is so
blatantly built in? I'm sure these things are programmed to show faults
they don't really have after a certain time.

At least some of the Epson inkjets *DO* have a built-in fault code that
kicks in at a certain volume of printing. Basically the overspray of ink
(and the ink wasted during head cleaning) gets absorbed into a sponge
stuck inside the printer, after "n" cartridge changes the printer
knows/suspects the sponge will have soaked up it's fill so puts up a
fault code suggesting it is returned to factory for maintenance (when
for most users it'll be cheaper/easier to buy a new one)

You can find the correct sequence to reset it on the net, but if you
simply reset it without emptying/replacing the sponge you risk the
excess ink overflowing and gunking up your desk ...