I've worked on one from ~2008. The fridge has a decent build quality, and two (!) compressors inside of it. It uses more metal components, more structural supports, etc, compared to most other fridges I've seen. So it's "better".
It also is designed such that you absolutely cannot clean the inner layers of the fan-cooled condenser coil without major disassembly of the fridge. The service panel on the front can be removed, but there is a metal fan shroud that is difficult to remove and turns what ought to be routine maintenance into an ordeal involving taking things apart and taking the built in fridge out of the wall. Whether this was deliberate or just an oversight, I don't know. There would have been many other simple and cost-neutral ways to implement this cover.
That is not what I’ve heard from speaking to appliance repair techs, or builders/architects, or the Sub Zero owners I know with 15+ year old refrigerators that have never had any issues (except the ice maker, which is an inherently unreliable piece of technology).
My guess is your friends aren’t maintaining them properly (they know they have to clean the condenser coils every couple months, right?) Either that, or they have those “integrated” models with no visible vent for the condenser, which of course will overheat the compressors and electronics.
They are a status symbols, that’s why they cost so much, not because they are top quality.