18 PB is not a trivial amount of storage. I think what most people always underestimate is how much engineering effort it takes in the background to keep such big infrastructure up and running reliably.

I would like to have a detailed total cost of ownership calculation. Of course, renting hardware - let's say in Hetzner or some other cheap provider - is always cheaper than AWS or any other major cloud provider in simple 1:1 pricing comparison. So that is nothing new. But the pure CPU/RAM/SSD costs is just a fraction of what it really costs to run such infrastructure.