My opinion: Kubernetes is a simple wrapper around Docker containers, that has a tremendous number of gotchas.
The overall concept is pretty simple: You create a deployment that spins up pods which are your containers. You create ingress and services to direct traffic to the pods. You configure it all with environment variables through ConfigMaps and Secrets.
However, there are still so many one-line commands you need to add to YAML or weird networking issues, or set of commands you have to type in each time, or permissions that are hard to configure and manage... And creating a cluster is a pain, unless you use something like kops. Great tool but it too takes a few hours to figure out even the basics.
I think in time, Kubernetes will get worked out. I love the core of Kubernetes. It took so, so long to figure out the rest.
That's my impression too. Kubernetes and Docker work very well together, so Docker knowledge is not out of date. It's just that Kubernetes is now relevant too. And more in demand because fewer people are fluent in it yet.
