Cloud is irrelevant. Its scope and repeatable results. A decade ago I had these problems with owned facilities, owned hardware, and dedicated internal teams. But it was thousands of hosts, multiple datacenters, and thousands of internal users. My personal break point is/was “a few hundred” hosts. Below that bespoke management can scale at a reasonable human:resource ratio. Above that you need too many people, and then you cant control or inspect the rate of change or variance.