Every command on this site has been run on a real machine before it was published. The Windows, macOS, and Linux tabs exist because the steps genuinely differ, not because it looks thorough.
Version facts such as which Java a release needs, which server.properties keys were removed, and whether a plugin has a build for the current version are checked against primary sources: the Minecraft Wiki changelogs, the PaperMC documentation, Adoptium, the Linux distribution package indexes, and each plugin's own download page. When something cannot be verified, the page says so rather than guessing.
Each page shows the date it was last updated, and that date only moves when the content changes. When Mojang ships a new drop, the setup tutorial and the guides are re-tested against it.