While it is _technically_ possible to build heavily decentralized, managed hardware deployments, no one has figured out yet how to charge for them except in the case of very large customers. Until this happens, there will be no swing back to anything decentralized.
Although I do understand the allure: just about anyone today could very economically purchase 5-10 servers with 10-18 cores each (and those will be _real_ cores, not hyperthreads). There's nothing impossible about automating software management on such a thing, even to the extent that you'd get in cloud (VMs, containers, distributed storage, automated updates, VM migration, network partitioning, etc). I believe Microsoft will lease you a fully set up shipping container with Azure in it, all that needs to be done is scale this down.
But again, how does one extract billions of dollars in profits from something like that?