Much less work than what?
Much less work than messing with Docker, Mesos, Kubernetes, Chef, Puppet, Rkt, Salt, Ansible, cfengine, etcetera... it's much, much simpler to build OS packages and keep the metadata needed to build them under revision control (git, Mercurial, Bitkeeper, ...) And as a bonus, it is designed to plug into the change management process from the ground up, and not as an afterthought. (Deployment automation and configuration management are not enough for complete lifecycle management.)
Thank you for saying this! Building OS packages and OS images and provisioning servers was done automatically 10 to 12 years ago with much less work.
It's still the preferred choice for many large tech companies and nobody talks about it because it just works and it's nothing new. Fast deployments, immutable infrastructure, modularity.