Plus a whole bunch of new operational techniques, security concerns, development paradigms, scaling opportunities, service offerings, integration possibilities,

Plus a whole bunch of new operational techniques, security concerns, development paradigms, scaling opportunities, service offerings, integration possibilities, failure modes, billing options. That phrase, "just someone else's computer", has long seemed to me a piece of recklessly dismissive arrogance. Engineering cloud-based systems is simply not the same as off-cloud, and assuming otherwise will lead to dissimilar outcomes.