> DNS is hierarchical with 13 root name servers.
It's a closed network, we can just hardcode everyone's address.
> Google is a private company, but if websearch ever goes offline, the utility of the Internet decreases dramatically. Some stupid percentage of webhosts are protected by Cloudflare; Cloudflare outages have taken large portions of the Internet offline. Same with AWS on the backend; when AWS has gone down, people find that a large number of the websites they depend upon go down too. Most people's consumer IPs are blocked off from the public Internet by their ISP and NAT.
All of this is irrelevant on a private network. I don't think you understood the comment you were replying to. The Internet is a bunch of little internets mashed together. Instead of mashing your internet with the others, you can provide services internally. No, other people's websites will not necessarily be on it, but they will anyway, because you'll probably provide a tunnel out to the wider internet. Anyway, you already have the internet, use it like you always did. The internet police don't make you give up the internet if you set up your own network.
You may not be able to appreciate the value of a communication system without access to google (you can download Wikipedia and serve it yourself if you find it a useful tool and your connection to the wider internet is endangered.) I remember an internet without Google, and I liked it more. The only thing Google ever did that was interesting was pagerank, and pagerank, being not resilient at all, was completely obsoleted by SEO. Everything else they've done has been a result of taking advantage of when they controlled an important market (access to the wider resource of the internet) for a few years over a decade ago.
When the internet goes down, my home network doesn't become either ridiculously difficult or useless. It will without pause or much notice still serve dozens of terabytes of data to anyone I allow to connect to wireless, and allow us to communicate with each other.
BBS's were useful.