For me, "on prem cloud" always sounds like buying a car and renting it back to yourself.
It’s a framework that makes it hard for one side to accidentally depend on something they shouldn’t.
Here i am just referring to the ease of using iaas offerings like s3 buckets but through on prem hardware. Devs build against drop in blob storage apis as if we lived in aws, and my ops guys still manage the backing vms.
"Like a cloud but closer to you" :)