You raised in my mind that we are looking at this all wrong, the server is not actually one component, it’s really a system of systems, and just like an airliner is a system of systems too, the conflict arises in that the comparison is at the wrong level.
It seems when people think of a server today, they think of a single computer, if not some software server somewhere in the cloud. These subject kinds of servers are far closer to complex systems of separate components, more like a network system, it’s why components of what are really separate networked computers can and need to be replaced.
An airliner is of course also made up of components that are also systems, however at least in my mind, the difference is the actual expected use case. An airliner is not a good comparison because it is never expected to remain in continuous operation, e.g., that at least one engine is always running even when it is being overhauled or repaired, to satisfy a requirement of continuous operation.