I think the point the author is trying to make is more so about these mini networks on their own LAN, which their family uses. (And maybe dreaming of a neighbourhood utility LAN as a middle ground between LAN in your house and WAN as just a trunk to a big ISP node) The full quote is

    - A Raspberry Pi 3B+ with a 3 gigabyte hard drive setup as a "server" (makes this site available on my home network[9])
    - I publish this site via GitHub Pages service for public Internet access (I have the least expensive subscription for this)
    ...
    [9] I can view my personal web on my home network from my phone, tablet and computers. So can the rest of my family.

There's a whole meme subgenre dedicated to this type of argument. Search for "Yet you participate in society, curious!"

Yes, but that person owns their website, its content, and the address it lives at. They can publish anything they want, in any format they want.

Hosting on GitHub is merely a convenience; they can up and leave anytime.

For reals. I love the general premise behind the article, but to me how you publish it, and how others access it, is the sauce. Creating static sites is hardly the problem.