The kubernetes folks describe a tentative solution to cloud lock-in here: https://kubernetes.io/docs/concepts/cluster-administration/f... OP isn't the only one with those concerns.
It would be nice when you can switch your cluster load from any of the cloud providers, or your own on-prem setup as you go. For instance, I could see people wanting to have a default small cluster on their on-prem setup, and be ready to scale on cloud when needed.