A ton of the value from k8s is in the programmatic and replicable configuration. 1 computer pets are still bad in a mom and pop shop. 1 computer livestock is still better.
After your single cattle is murdered, the next one has to be raised right?
State has to come from somewhere. Downtime has a cost for most businesses.
But being able to blow away a k8s node and bring it back up in 2 minutes (or have k8s auto-spawn a replacement node) is WAY faster than having to reinstall wordpress, reinstall nginx, set IP addresses, fiddle with your DNS, restore a database from a backup, etc, etc, etc.
Kubernetes just makes that story so much simpler. Heck a good cloud provider can just handle any machines fucking up automatically without any human intervention on your side.
The same can't be said for a single machine.