Although, to be fair, the article is about GKE.
But literally every cloud provider out there has a managed solution so at this point you really only need to do it for DC work or if you like to do it.
Amazon - EKS Google - GKE Azure - AKS
anything beyond those 3 is a rounding error but...
Linode - LKE DigitalOcean - DigitalOcean Kubernetes IBM Cloud Kubernetes Service Rackspace - KAAS
Creating a big-ole cluster of app servers was never really the hard ops problem which is what k8s does really well.
The benefit of k8s is the orchestration of those clusters. Spinning up 6 new http servers and getting them added to the load balancer automatically. Generating 4 new memcached nodes and getting them registered in DNS so clients pick them up and add them to the hashring.
The benefit of k8s is the scaling and elastic capabilities. It can trigger vertical scaling by spinning up larger pods or horizontal scaling by adding/removing pods.
Anyone thinking that people are using k8s because it can create app servers doesn't understand why anyone is using k8s. If all we needed to do is create a cluster of app servers, we wouldn't be using k8s.
That being said, a cluster of app servers still needs orchestration and config management and we had a ton of crazy solutions for that prior to k8s.