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.