I disagree with that. Many fortune 500s are running k8s to power critical infra. GMF processes all OnStar data in realtime on k8s, GitHub runs entirely on k8s, etc etc. You need the personal and the tools to manage it, but at a certain point k8s makes sense. There are still use cases were k8s is not a solution.
EDIT: part of actions, codespaces and packages are not run on k8s, but 80% of github services are
EDIT: part of actions, codespaces and packages are not run on k8s, but 80% of github services are