The other perspective on this is that, at some level of your system you are always doing a hot code reload: terraform, kubernetes, etc. are taking a new deployment description in and reconciling it with the existing state of the world. Wouldn’t it be nice if this process was just more code in your preferred programming language rather than YAML soup?

BEAM encourages you to structure your program as isolated interacting processes and so it’s not that far from a container runtime in itself.