Fair enough! The danger with disks however is that it's an entirely manual operation which is easy to forget. Something setup-once-and-forget - local server or a cloud-based one like backblaze - is more likely to actually have the latest data when you need it.

(Another reason is that the disks do bit rot however, and you'll never know until it's too late. Meanwhile, my ZFS fileserver sends me a email every weekend that it's scrubbed all the disks and found no errors - this warms my heart :) )