Barbarians at the gate, Google and Amazon slurp it all up eventually. How's those big ones feel inside your budget, Apple.
Its a million drives. given the failure rate that I had when I was looking after 5 pb,(about 8k hdds) you'd be looking at at least 100-400 failed drives a week
But how do you detect that, how do you schedule replacements? whats your hamming factor for redundancy, how do you optimise your storage? for speed, power, geospatial, or redundancy?
what about capacity management, the lead time on growth would be large.
I was a sys admin for a large VFX place, so did a lot of storage admin, but unless it was a core business function, I'd buy over build that shit, for that scale.