I hear more and more cases of businesses moving parts off of the cloud, back on-premises. I think, in a wider perspective, it's going to play back and forth. The 2010's were 'forth' towards the cloud, the 2020's might see a peak back on-prems, etc.

It's generally a function of network cost versus infra cost, and so the 'equation' solves differently based on the longest tech cycles, from inception to maturity to skill pool to diminishing returns and then back again on some other mode — this really is a decade+ thing.

Some "always true" inherent advantages of one approach (e.g. availability for cloud, or resources for on-prems) would remain across cycles as permanent gains; disruption then occurs when some new approach (e.g. containerization) fundamentally upsets the order of costs.