New servers are also super expensive, and don't directly market to consumer, but their used value is basically nothing. You can buy a used server on eBay, even with relatively nice specs for a consumer, for less than a grand, often substantially less than a grand (mine was $150 for 128gb of RAM and 24 cores).
It doesn't appear that pro-grade cameras fall the same way though.
I wonder if cameras are just too durable and don’t need to be upgraded as often?
Even a consumer camera will last you roughly forever in my experience. I still use a DSLR from 2015 that works great and does everything I need.
A nice 4k (and especially 8k) camera, on the otherhand, is likely "good enough" for a lot longer. A studio can probably get a lot more value out of a 10 year old Red One than a trading company can get from a 10 year old server, so there's not really the constant need to upgrade your camera every year or two.
Also, it would be worth considering that a new camera would (I assume) require a bit more learning on the operators part, since there might be subtle differences between color grading and compression and the like. A server, on the other hand, is somewhat standardized; Linux is basically Linux, if you're running the same OS you're getting basically the same experience, so the process of upgrading is pretty easy.