The the original commenter but I'll jump in: 1. While "we already rely on VM staying up", with k8s we reply on both VM staying up and kubernetes infra on top o

The the original commenter but I'll jump in: 1. While "we already rely on VM staying up", with k8s we reply on both VM staying up and kubernetes infra on top of that VM staying UP 2. Maintaining a complex stateful system on k8s _requires_ having and maintaining an operator for that system. 3. You reduce your options when it comes to tweaking systems, e.g. local SSDs on GCP are available in SCSI and NVMe flavors, while GKE supports only SCSI; harder to perform fine-tuning and other tasks on the underlying VMs that would have been trivial with Chef or similar. 4. Enterprise systems like Splunk explicitly mention that their support does not cover Splunk clusters running on kubernetes. 5. As mentioned, you can't even resize a disk without going through dance of operations that would take days or weeks when you're working something like Kafka at scale. 6. Some stateful services like Zookeeper require stable identities and this is far from perfect on kubernetes. 7. More complex traffic routing that involves additional fees because to achieve (6) you sometimes need to expose things publicly. That's just from the top of my head. Disclaimer: We run 10+ stateful services on Kubernetes.