"Economics 101 lets you know that cloud will be less costly and better than on prem"
Let me guess, you also believe - despite mountains of evidence - that trickle down economics works.
And the earth is only 4000 years old. The eye is irreducible complexity. *thud* *thud* *thud* *thud*
"Everyone knows this intuitively. If I were to ask you if it would be less costly to purchase network services from an ISP like Verizon or bury your own fiber lines underneath the ground/oceans around the world, everyone would say that obviously it is going to be a lot more cost effective to just rent lines from the ISP where many people share the cost burden than to pay billions to create your own global network...."
Um...you're demonstrably wrong. Massively, demonstrably wrong.
First off, it's cheaper to build your own global network the instant the cost of laying your own fibre gets to about 1/20th the cost of renting it. Right about there you can go lay multiple strands of cable, use whatever capacity you need and rent out the rest.
You know, like Google does. Sure wasn't cheaper to just stand up their own datacenters and pay the rent to the ISP. Nope, they laid their own fibre. And yes, they even have a stake in oceanic cable.
I can introduce you to municipalities that also lay fibre for everything from last mile to backhaul. I can introduce you to WISPs and even businesses as small as 10 people who would rather pay the municipal fees to dig a ditch to lay fibre between their location and the local internet exchange than to pay the ISP. Shock, horror...it turned out to be significantly cheaper.
In some cases the ISP is cheaper. In many others it's not. Just like in some cases (you know, those very rare niches where you have "could native" burstable workloads) the cloud is cheaper. In many others (such as 24/7 workloads), it's not.
As with everything in IT it depends. You do a needs assessment and you use the right tool - technical and economical - for the job. You don't decide on the tool and then contort all reasoning beyond logic in order to fit what you do to that tool.
Also - and I don't understand why I have to keep repeating this to someone supposedly so smart - there are huge differences between regulated industries (like telcos) and completely unregulated ones (like public cloud services). What my governments impose on telcos here as minimum service quality, pricing caps and more keeps monopolistc behavior in check. There is absolutely nothing keeping monopolistic behavior in check amongst the cartel of public cloud providers.
Also - and again, I can't understand why this is so hard for you to get - when you do the actual numbers on running your own workloads you don't have to be running that many workloads 24/7 before rolling your own is significantly cheaper than public cloud.
Religion. All you're touting here is religion. It is no different than trickle down economics or praying the gay away.