Docker as in package internal services as a container then having them deployed to a cluster which handles orchestration for you great. Your internal service, microservice if you want to call it that just becomes a process deployed to a bunch of nodes and you have a common immutable deployable asset.

Docker as in downloading random images of Dockerhub and plumbing them together. Not so great, quality varies and most people don't actually check what they are really running. Often they are VMs packaged up as a container, badly.