Interesting take on the freely available SMART data that backblaze freely shares. What caught my attention is the overall low read/write speeds of the drives, less than 1 MB/sec which is quite low even for mechanical disks.
Perhaps the HDDs aren’t being utilized as much as they could be, which in turn affects their lifetime.
In the context of their business -- ingesting data that will never been read -- and architecture[1], low average transfer per disk is to be expected. Prior to the v5 Pods[2] they were on 1GbE networking as well.