I ended porting a few clients we had in a company that were already running based on Docker to a Kubernetes cluster. The major issues were trying to push everything there. I think it works very well to manage web clients.
Problems started by trying to push too many things into the clusters. Databases and specially ElasticCache with Kibana to collect metrics from the cluster ended killing the performance.
So it's like everything, some cases are great for K8s, some are terrible. This + a complex abstractions makes it not that developer friendly, but overall it does a good job to run and allow to scale services without having to worry too much with hardware.
Problems started by trying to push too many things into the clusters. Databases and specially ElasticCache with Kibana to collect metrics from the cluster ended killing the performance.
So it's like everything, some cases are great for K8s, some are terrible. This + a complex abstractions makes it not that developer friendly, but overall it does a good job to run and allow to scale services without having to worry too much with hardware.