The cynic in me says this was written by sales/marketing people targeted specifically at a whole new generation of people who've never laid hands on the bare metal or racked a piece of equipment or done low voltage cabling, fiber cabling, and "plug this into A and B power AC power" cabling.
By this, I mean people who've never done anything that isn't GCP, Azure, AWS, etc. Many terminologies related to bare metal infrastructure are misused by people who haven't been around in the industry long enough to have been required to DIY all their own infrastructure on their own bare metal.
I really don't mean any insult to people reading this who've only ever touched the software side, but if a document is describing the general concept of hot aisles and cold aisles to an audience in such a way that it assumes they don't know what those are, it's at a very introductory/beginner level of understanding the OSI layer 1 infrastructure.
I wanted to start off with the 101 content to see if people found it approachable/interesting. He's got like reams and reams of 201, 301, 401
Next time I'll stay out of the writing room!
When the original aws instance came out it would take you about two years or on demand to pay for the same hardware on prem. Now its between two weeks for ml heavy instances to six months for medium CPU instances.
It just doesn't make sence to use the cloud for anything past prototyping unless you want Bazos to have a bigger yacth.