It is related because a naïve program will access a device (CPU registers, instruction pipelines, indirect cache access, RAM, disk, optical disk) in a linear fashion. RAM no longer has linear or near linear access. Disk drives of all types dealt with rotation speed, spindle head speed, etc. For a long time, disk specs were recorded in linear/sequential access time, full seek access time, and average random access time until sequential access time became less than 1ms and OSes/disk cache programs made average random access time the only latency worth caring about.

In summary, most storage devices have hierarchical performance and it’s worth caring about how to optimize for that.