I think hyperscale margins are high, and I think between the many tiers of storage and backend technology they are constantly cooking cost out.
The highest speed storage is cheaper than ever and getting cheaper. That’s the expensive stuff. Our “big” high speed storage array was like $5M in 2012. Now it’s like 10x bigger, 5x faster, and 40% of the cost.
Bulk spinning disk prices drop at a slower rate but historically they are performance bound. The marginal byte of cold data has no marginal cost, as you always have lots of space on disks where you’re short on IO budget.
Really cold workloads that need to live on-prem for reasons and need to be retained for 30+ years can go even cheaper. That stuff lives on tape at a lower price point, like a half penny per raw gig.