I would say they are complementary. Kubernetes is a standard solution for packaging and deploying apps. If you run a lot of apps, you want your ops team to be able to manage them without knowing all the details. You get better utilization of your servers by allowing them to deploy standard units and manage resources at a higher level.

You can put an Erlang/Elixir app into a container and deploy it, but containerization doesn't provide as much value as it may for other languages. The Erlang VM doesn't depend much on the operating system. The mix build tool tightly manages runtime library dependencies, and building a release combines the VM and the app's libraries into a single tarball that you can deploy as a unit. So we don't find it particularly useful to use Docker/Kubernetes to deploy.

Erlang/Elixir makes it very easy to take advantage of all the CPU cores available, so you generally benefit from having one instance with lots of CPUs instead of lot of little instances. And it can be a lot cheaper to do this in a dedicated server environment instead of the cloud.

So on the whole, Kubernetes is not that big a win for Erlang, but they work fine together.

I also want to know this. We have a team of 3 people maintaining our microservices infra (services written in NodeJS), out of ~15 developers. It feels like a waste, these (monitoring, logging, deployment etc) are all problems that have been solved many times over.