Yeah, the Emperor's New Clouds. Sometime ago I thought I was crazy and everybody else was right :-) but now we are seeing more and more people doing the numbers.
You could do configuration management in the 90s with rdist well enough on 100 servers. The problem with IT in the early 2000s was that IT departments were shoveling money to companies like VMWare and EMC and overbuilding all their hardware. Amazon built everything on commodity hardware and open source and didn't have vendors acting like financial boat anchors on their scalability. IT departments also usually had massive amounts of friction and gatekeeping to getting anything done, and you needed a design review meeting to spin up a single server for someone. And really I think it was elimination of that centralized control and bureaucracy that made cloud computing so popular.
https://logical.li/blog/emperors-new-clouds/
I wonder, though, why the topic is so contentious. This is supposed to be an engineering discipline, not a fight between religions.