So the chandelier looking thing is a dilution fridge and is just used to make the processor cold. The processor is usually pretty small, not that different from your CPU. That part is indeed iterated on but the fridges aren’t changed much. The wiring is sometimes switched out, but the fridges get used forever. I’m using one now that’s maybe 30 years old. The dilution units are very hard to make, and there’s a very small academic family to which everyone who can make one traces back to.

They mostly hang like that since most dil units are designed so the coldest part is usually the lowest, and they’re generally orientation sensitive. You want easy access to the bottom part, so you just put the plates in descending order of temperature and you hang the thing from the ceiling.