I’ve had the pleasure of contracting on a cloud migration project, and then a little while later an on-prem migration for the same project. I helped that company build a cost model for comparing their on-prem and cloud workloads, and they ended up moving quite a bit back on-prem. Even for the workloads they didn’t move, having a better way of comparing on-prem and cloud TCOs helped them negotiate much better pricing for their remaining cloud workloads.

One legitimate challenge is that it’s actually rather difficult to measure the TCO of each option. I’ve seen companies pushed to get better at that as they experience cloud sticker shock, and as large enterprise pushes more and more work to the cloud, I’d expect to see them continue to improve in this area.