1. It does list some completely valid options which are good to know. All of them are interesting both from the perspective of learning about more Linux internals and actually locking down access where needed.
2. It mixes security and privacy. Some privacy things may be interesting, but going as far as removing your machine-id? What's the scenario here exactly?
3. It tells you what you can do, but often doesn't say why. What's the threat model? It bounces between things that could be useful for the desktop and for the server. If you're protecting yourself at home, what exactly does blocking ICMP provide you, given it's likely both a flat network and you're registered in both upnp and mdns?
4. Some points I find really questionable: It says to avoid distros with systemd, however systemd was the first one to really bring service sandboxing to the masses. So many issues could be avoided if we used PrivateTmp years ago. Some points are really bad: Avoiding distros that freeze packages (I guess vs rolling distros) is not a trivial change and is not obviously more secure.
5. https://xkcd.com/1200/ - Sure you can put all of those extra options in kernel boot, the extra layers of service separation, spend time hiding identifiers and network options. Unless you're specifically targeted, nobody will ever try that. You'll be owned by some XSS which pulls your login cookie - and the list doesn't even mention Firefox tab containers which can separate that content. Or if someone's targeting developers, your SSH key will get extracted - and the post doesn't even mention hardware SSH keys.
Overall it reminds me of CIS policies. "Here's a CIS certified docker image. It has aida and tcpwrapper on it, because security."