I believe we already do this

You can write shares to CIDR blocks e.g. 100.0.0.0/8

Oh I know, I had the same thoughts

Object storage does really bad as a filesystem and it may very seriously be cheaper for you to have a 5TB storage box over 2TB of object storage

S3 has no list operation, so any time the computer wants to “list” a directory in object storage that is expensive

I have a similar use case and whilst I’m not quite there yet I’m intending to go with a storage box

I think you just contradicted yourself in that same sentence