This is exactly what we [1] do! We migrate clients out of AWS and into Hetzner bare-metal k8s clusters, and then we also become the client's DevOps team (typically for a lot less than Amazon charges)

I will say that there is a fair bit of lifting required to spin up a k8s cluster on bare metal, particularly for things such as monitoring and distributed block storage (we use OpenEBS). I would ballpark it as a small number of months.

It is likely easier on their cloud offering, but we've found that to be a little less reliable than we would hope.

Happy to chat more: adam@...

[1] https://lithus.eu

I'm using AWS for small k8s clusters. I stay away from most of the "managed" AWS products except S3 and ECR. My k8s stack is packer + tofu + k3s + zfs: It's easy, concise, self managed, and costs are easy to predict.

You might also want to review https://loopback.cloud for that purpose