You can argue about the configuration-based deployment being worth it--I disagree, because, frankly, Chef Zero is just not that complicated--but it's more expensive in every use case I have seem in the wild (barring ones where instances were unwisely provisioned in the first place).
K8S/docker also makes it easy to avoid all the systemd/init issues and just use a standard interface with declarative configs and fast deployments that are automatically and dynamically managed while nodes come and go. We have preemptible instances with fast local storage and cheap pricing that maintain 100s of apps. K8S also easily manages any clustered software, regardless of native capabilities, along with easy networking.
Why would I use chef for that - if it can even do all that in the first place?
Just a historical perspective: GCE used to charge a flat fee for K8s masters after 6 nodes. After the announcement of the Azure K8s service, with no master-fee, GCE has dropped the fee as well :)
Kubernetes does really well with this, although ease of deployment using config files and the abstraction from underlying vms/servers is probably more useful for most companies.