Docker, yes, but kubernetes is way more than that the instant you have more than one physical machine node. (If you only have one node in any deploy, sure, it's likely overkill, but that seems like a weird enough case to not be worth too much ink.)
If you silently replaced all my container images with VM images and nodes running containers with nodes running VMs, I think the vast majority of all my Kubernetes setup would be essentially unchanged. Heck, replace it all with people with hands on keyboard in a datacenter running around frantically bringing up new physical servers, slapping hard drives in them, and re-configuring the network, and I don't think the user POV of how to describe it would change that much.
