I really like this description of how baremetal infrastructure should work, and this is where I think (shameless self promotion) Triton DataCenter[1] plays really well today on-prem.
PXE booted lightweight compute nodes with a robust API, including operator portal, user portal, and cli.
Keep an eye out for the work we are doing with Triton Linux + K8s. Very lightweight Triton Linux compute node + baremetal k8s deployments on Triton.