Most of them in my experience. Many industrial machines have lifespans well beyond 15years. Big companies buy the state of the art and when they decide to replace the old machines they resell them to smaller companies who can't afford to buy the newest model.
I know many people on HN work in web technologies where last year's technology is already obsolete but I've worked in small hardware companies that still used industrial equipment controlled using a serial keyboard with a DIN connector and a monochrome CRT. I've seen people order parts for 20+yo industrial soldering ovens.
You can't really tell somebody with a highly expensive, perfectly functioning industrial machine that they have to buy a new one because you can't find the driver for the motherboard of the controller.
Back in my IT days we used a laptop that had a windows NT 4.0 sticker on it (running windows 2k) to run the ID printer that printed company IDs. These kinds of setups aren't that uncommon. At small scale it's easier and cheaper to keep old stuff running than to migrate.
I work in Manufacturing IT, I can confirm that there is considerable legacy equipment. Thing is, these machines typically cost more than a house, some as much as $2.5M+ dollars. Would you demo your house and rebuild in 20 years because of a leaky roof? These machines are mortgaged the same way, the bank secures the asset. They will work for 20+ years if you maintain them, and continue to produce.
Basically all scientific research labs use some equipment running windows xp or older because the drivers can't be installed on modern windows for one reason or another. Controllers for things like spectroscopy, electron beam microscopes, centrifuges, etc. Custom control boards are also common in industrial (oil, gas, chemical processing) applications.
I once spent an internship running a fluorescent dye laser operated by an computer running DOS (maybe MS DOS?). It was terrifying, but the beast worked perfectly well.
And my PhD lab was using mass-spectrometers that still required vacuum tubes.
Companies other than Intel are continuing to pursue irrelevance for industrial or high-stakes operations themselves.
Sometimes you've got to have a Bozo when a competitor or associated business has one or more Bozos in a decision-making position.
Just to be seen as competitive or up-to-date.
Apple and especially Microsoft made more money from anti-recycling after they pushed it into a position where the original superior engineering was not as lucratrive for the shareholders.
Users should be grateful since they were not squeezed more thoroughly even sooner.
