I think lower cost of capital is a narrow metric and rarely reflects the real total cost of ownership once you account for ops headcount, provisioning lag, redundancy requirements, patching, and developer time.

Cloud looks expensive on sticker price, but it buys instant provisioning, autoscaling, managed databases and multi-region DR, and those benefits only pay off if you actually exploit autoscaling, reserved or savings plans, spot fleets and cost tooling like Kubecost or AWS Compute Optimizer to enforce right-sizing and kill zombie instances.

If you want cheap dev and UAT keep them on on-prem metal or cheap colo, but automate with Terraform and run reproducible runtimes like k3s or devcontainers so environments stay consistent and you do not trade lower capex for a creeping operations nightmare.