A few years go now Western Digital demonstrated an onboard controller with two 1 GB NICs and a mini linux distribution with a single Ceph OSD installed. Unfortunately it never made it out of the lab. I would gladly pay a $50 premium per device for spinning rust to have that onboard. Perhaps the issue is with NVME-connected devices that could be a much costlier device to build? Or maybe there's no standard for housing network-connected storage devices in a rack?