Kubernetes just orchestrates containers. You can still run beefy machines and scale (if necessary) accordingly.
If anything, Kubernetes allows you to save cost by going with a scalable number of small, inexpensive, fully utilized machines, vs one large, expensive, underused one.
I would wager that the majority of users of k8s do so on a cloud where they could provision VMs of the proper size to begin with. The utilization argument is specious.
