I would honestly be interested in what the author(s) consider to be the advantage of such a setup over things like for example GitHub Pages, Netlify, S3 + Cloudfront, a plain Apache Server?
"The goal of this tutorial is not to show you that you need a Kubernetes cluster to run a static website, it’s to show what can be done with OpenFaaS and Kubernetes."
I don't think it is being advocated that you should make this switch, just an informative article showing the steps required to do so.