Sure, but even then, on the server - where the storage medium exists, and the bytes are held - it's stored on the operator's choice of filesystem, made possible

Sure, but even then, on the server - where the storage medium exists, and the bytes are held - it's stored on the operator's choice of filesystem, made possible by the ubiquitous block IO interface (or the platform-specific equivalent thereof). Edit: Network block device, iSCSI, AoE, etc... the block interface is the lifeblood of the storage area network.